Tanjiro comes from a family of fishermen. His family has lived up on Mt. Kumotori for centuries living off the land and lake there. Ever since he could walk he had helped his father fish from the expansive lake by their home.
Until recently.
Until Tanjiro began to experience certain changes brought on by the water.
At first, they were small. Like when reeling in the nets with his father and younger brother, Takeo, he would notice small, translucent, scale-like patterns forming on his skin where he had been touched by the wet netting. Or when he would get his hands wet and he swears the skin in between his fingers would thicken.
But it all came to a head one night when he went out on the water alone.
He took the rowboat out instead of the normal fishing boat. He was only heading out to check the nets for the night so there was no need to take it. The rowboat was easier to maneuver by himself anyway.
That night he rowed himself onto the water not knowing he would return a completely different person.
He had finished checking the nets and was about to head back for the night when he saw something on the water. Well, it wasn’t exactly “something” it was the reflection of the full moon against the dark tide. It was beautiful.
It was hypnotizing.
Without thinking, without breaking eye contact with the moon's pale reflection he shed his clothes and dove into the dark water.
That’s when the transformation happened.
He felt gills open up along the sides of his neck and ribs. His nails elongated into claws and he felt his teeth sharpen in his mouth. His ears stretched out into crimson fins and his fingers became webbed with that same scarlet tissue. Matching fins and scales fanned themselves out along his forearms. His legs began to grow scales as well as they fused into a deep red tail with a large fin at the end of it and a long dorsal fin sprouted down his back.
He hates to admit this but the rapid transformation felt - good. The transformation itself felt like a deep stretch when you get up in the morning. When his gills opened and filled his lungs with water for the first time it was so much more refreshing than the cool mountain air he’d grown accustomed to.
The transformation felt - freeing.
It took him until he resurfaced to fully realize what had just happened to him.
What had just happened to him?
What was he?
Panicking, he scrambled back into the rowboat. Neary capsizing it several times in his haste. And there, in the soft, white moonlight he was able to see the extent of his transformation for the first time.
He looked down at himself - at his new body - and clapped a hand over his mouth, which was agape in unrestrained horror.
His legs had been replaced by a long, crimson fishtail that draped over the side of the boat and into the water. His back hurt. He was sitting against something uncomfortable. He gingerly rolled onto his side and watched in horror as that red, serpentine tail slithered and responded to his movements. Worse, he could feel it. He could feel the wooden boat beneath the smooth, slippery scales. He could feel the crisp, night air flutter against it.
Against his tail.
This was his tail. He scanned up and down the new appendage as if to search for his legs. He had a tail. A large, blood-red tail that had to be at least eight feet long.
Before he could panic he became overcome with a violent coughing fit. He roughly started to cough up mouthfuls of water.
Water. His lungs were full of water.
He was breathing water through his gills and now his lungs were full of water.
After a few minutes of constant and painful coughing his lungs seemed satisfied and Tanjiro took a few gasping breaths as he got used to breathing air again.
He reached a shaking, webbed hand and touched the side of his neck remaining careful of his new claws. His gills had remained tightly shut since he resurfaced but he could still feel the long slits across his neck where the openings were.
He shivered at the new sensation. The skin there was thinner and more sensitive than the rest of his neck. It was more similar to the skin of his eyelids.
He brought his shaking hands out in front of him. He had pale red, semi-translucent webbing between his fingers, and at the ends of them were claws. Sharp and strong, easily capable of causing serious harm.
He followed the garnet scales up his arms and found more fins growing from his forearms and upper arms.
Something was pressing against his back again.
With some difficulty, he managed to roll himself over and look over his shoulder. He didn’t see much but out of the corner of his eye, he could see more of that horrid blood-red color.
He reached a hand behind him and felt along his spine, again, being weary of his claws. He cringed as he felt along the base of a huge dorsal fin. It was strong yet flexible and perfect for cutting through the water.
He took his thumb and felt along the sharp, serrated teeth he had grown. God, they were sharp. They felt large and unnatural in his mouth.
He looked back down at his hands again.
He was built to hunt. He had become some sort of wild and violent predator.
He was a monster.
He looked down at himself - at his new self - and cried.
He cried because he was scared because he didn’t know what to do, because he didn’t know what was happening to him.
He didn’t know how long he sat there and cried but eventually, he felt himself start to change again.
He froze as he was overtaken with fear.
Again? He’s changing again?
His fear quickly dissipated as he watched his fins begin to fold back into his skin and his tail shorten and separate back into legs as he once again regained a more human form.
He had to reach down and touch his legs before he fully believed they were back.
He took a couple of shaky breaths as he tried to ground himself. He never felt so terrified and relieved at the same time. He was terrified of what had just happened to him, and didn’t know if or when it was going to happen again. But, he felt relieved because, whatever this was, it seemed to be over. At least for now.
He dressed himself and rowed back to his now worried parents. As his home came back into view he could make out his mother standing on the docks with a lantern waiting for him.
She embraced him with open arms and a watery smile. He sheepishly apologized and said he had simply lost track of time while stargazing. She forgave him. She was just relieved he was safe. He then headed inside to try and get some sleep for the rest of the night.
————————————
That was the last time he went on the water.
He was terrified of transforming again. Or worse, transforming in front of his father or younger brother. He didn’t want anyone to see him like that, especially his family. He didn’t want his family to hate him. The thought of his family finding out what he was and being as afraid of him brought him to tears.
He had been acting ill the past four days to get out of helping his father out on the lake. He felt terrible about it because his chores and duties then fell onto Takeo. He also rejected his mother's offers to draw him a hot bath or put a damp cloth to his head.
He did nothing but lie in the bedroom for four days.
That changed this evening.
After his mother, father, and Nezuko put all his siblings down for bed, his mother and father asked him to come outside and sit with them. He agreed and his father helped him up as he pretended to be sickly and weak.
He thought they were going to simply sit outside on the porch. His anxiety began to rise as they headed for the docks. Sensing his growing unease, his mother spoke up.
“We just wanna sit with you out on the lake. We think some fresh lake air will help clear your head.” She said sweetly. It didn’t help his stress. He didn’t want to go out on the water. That was the last place he wanted to be, but he didn’t know how to protest it and if they were just going out to sit on the water there was a low chance of him getting wet.
He could feel his heart beating in his throat as he boarded the small rowboat with his parents. Silently, they made their departure. Tanjiro could feel the weight of the air around them. His parents weren’t speaking or even looking at each other as they rowed further and further away from the shore.
Tanjiro didn’t make eye contact with them either. His eyes were fixated on the floor of the boat. Right at the spot where he had ended up after resurfacing from his transformation. Right at the spot where he mourned his own humanity that night.
They finally stopped and his father spoke up from behind him.
“Tanjiro?” his father asked softly. “Can you tell us what really happened that night you were out late on the lake?” Tanjiro felt his heart stop and his blood run cold in his veins.
“You mean the night I stayed out doing some star-gazing?” Tanjiro responded shakily, reaching a trembling hand up to scratch the back of his neck.
“Yes, that night.” His father confirmed quietly. “Tanjiro, your mother and I have noticed you haven’t been back on the water since that night.” He said, his words heavy and serious.
“And it's not just the lake you’re avoiding either,” His mother spoke up. “You’re avoiding water at home too.” She said, her words were thick with concern and worry. Tanjiro felt terrible for causing his parents distress, but he couldn’t tell them. He couldn’t tell them that their eldest son and firstborn was some inhuman thing.
He balled his hands into fists and tried to get control of his breathing. This was not good. This was not good. This was not good. He was panicking. His head was spinning. He didn’t know what to do. He didn’t know how to get out of this.
“Tanjiro?” His father leaned in and put his hands on Tanjiro’s shoulders. His hands were grounding and warm against the cool lake breeze. “Tanjiro, it’s okay. Tell us what happened.” His father asked gently.
He began to cry. He really didn’t have a choice, did he? He was going to have to tell his parents about what he’s become. Crying escalated to sobbing and he slumped over and put his head in his hands.
“I don’t know.” He choked out. “I don’t know what happened.” His father leaned in and held him as he shared a sad yet knowing look with his mother.
“It’s alright, it's alright.” His father quietly cooed as he rocked them back and forth to the rhythm of the waves.
His mother joined them, she draped herself over him and his father. Sat there between both of his parents with his father whispering soft reassurances to him he felt safe. He felt loved. His sobbing calmed back down into quiet crying. He felt like a small child again, crying as his parents held him.
He sniffed and sat up, wiping his face on his sleeve. His parents sat back in their respective seats. He took a deep breath and steeled himself for the conversation to come.
“I don’t know what to say. I hardly even knew what was happening to me before I-“ He choked back a sob and stared down at his own shaking hands as if he didn’t recognize them. “I’ve become a monster.” he rasped.
His father grabbed his trembling hands and pulled him back into a hug. “You’re not a monster, Tanjiro.” His father said firmly. “But, we- we think you may be a water spirit.” He continued.
“A water spirit?” He whispered into his father's chest. He felt his father nod above him.
So he was a water spirit.
A water spirit is a creature that most doubt even exists, belonging more to myth than reality. Very few humans encounter a water spirit in their lifetime, and those who do are considered to be both extremely blessed and fortunate. Water spirits were considered good omens and healers of disease. And he- he was one of them?
Was he some ominous and otherworldly creature? He just felt like, like him. He was the son of a fisherman. He was a brother to his human siblings. How? How did he end up like this?
“How?” The question slipped out before he even knew he was asking it. His father shifted him in his grip a bit.
“Centuries ago, one of your mother's ancestors fell in love with the water spirit of this lake,” he began to explain. “Generations went by and another water spirit was never reborn into the family. Your mother and I simply excused the story as a legend but-“, he looked down at Tanjiro. “If the story is true and the blood of the water spirit still runs in the family bloodline it’s possible that you or any of your siblings could be born a water spirit.”
Tanjiro stayed curled up against his father as he let that information sink in. So that's what happened to him that night. He started to mature into a water spirit.
Water spirits weren’t evil, or at least, very few of them were. People prayed to water spirits, either for good health, rain, or good fortune.
“You don’t hate me?” Tajiro asked quietly, scared of his parents’ answer.
He was immediately answered by his mother who joined him and his father in the hug.
“No sweetie, we could never hate you. Not over something you couldn’t control.” She responded earnestly.
Tanjiro moved to wrap an arm around each of his parents. They knew what he was. They knew how different he was from them and they still accepted him as their son. Again, his eyes began to well with tears.
“I love you both, so much.” He sobbed.
“We love you too,” his mother promised. “Tanjiro?” His mother asked after a brief period of silence. He looked up at her with large, expectant eyes. “Was the last time you were in the water four days ago?” A sheepish blush crept its way across Tanjiro’s face. He nodded in response, not looking her in the eye. He was still embarrassed about being different from his family. Even though they accepted him for it he was still embarrassed.
“We think you should transform out here before we head back.” His father stated. “We don’t think it’s a good idea for you to avoid the water for extended periods of time.”
“Oh! I-,” Tanjiro began. He didn’t want to transform in front of his parents, but at the same time, he still agreed with their point. Ever since that night, his body craved the liberation that was his other form. “I guess I can do that,” He supposed they would have to see him at some point. “Could you please look away for a moment?” He asked them. They both nodded and shielded their eyes.
After taking a moment to gather his courage he stripped himself of his night clothes and dove into the cold, black water.
The transformation felt both odd and inordinately as much as it did natural and comforting. A blend of alien sensations all combining to turn him into something otherworldly. He stretched his fins and took a deep inhale through his gills taking a brief moment to appreciate the sensations of his new body.
He gently resurfaced and looked between his parents. They were both sitting there with their eyes closed as promised. He took a moment to prepare himself. He couldn’t hide himself forever. “Okay,” he gave them the confirmation to open their eyes.
Slowly, hesitantly they each opened their eyes. They seemed just as scared to see this side of Tanjiro as he was to show it to them.
The first thing he saw in his parents' faces when they saw him for the first time could be described best as shock and awe.
“Tanjiro-,” his mother said breathlessly. His ear-fins perked up at the sudden noise. He didn’t miss how his parents' eyes lit up when they noticed the movement. “Tanjiro, you’re beautiful,”
Tanjiro blushed and let himself sink slightly deeper into the dark water. His ear-fins flattened themselves to the sides of his head in a display of bashfulness. Of all the things he was expecting to hear from his parents, his mom telling him he’s handsome, was not one of them.
His mother rolled up her sleeve and reached out to touch his face, stopping just before as if to ask for permission. He didn’t hesitate to let her cup his cheek. She ran her thumb over some of the ruby-like scales that framed his face. He watched as her eyes swept over him, taking in all his new details and features.
It was strange. It felt like his parents were meeting him for the first time.
In a way they were.
They had never met a water spirit before. They had said it themselves, they hardly even believed they were real before their son became one. And now here he was, this mythological creature sitting right in front of them.
His parents were staring at him with such amazement. It felt odd to be so revered, especially by his parents. He had always looked up to his parents since he was a boy and now to have them looking at him like this. He didn’t like it. Is this how everyone would look at him from now on? If they ever told his siblings about him would they look at him the same way? Would they stop seeing him as their older brother?
“Am I still your son?” He asked quietly, sinking into the water as he looked up at them with large, watery eyes. His parents shared a quick, confused glance.
“Of course Tanjiro. Why-?” His father answered with concern.
“Because I’m not like you!” He cried. “Because I’m- I’m so much different from you guys. How can you still see me as your son? You- you looking at me like- like I’m-,” His lip began to tremble and he reached up and covered it with his hand.
“Tanjiro,” His father reached out and took his hand. “I couldn’t be prouder to call you my son.” His father said as he held Tanjiro’s scaled, clawed, and webbed hand in his large, warm, human hands that were calloused from years of manual labor.
He stared at the difference between his hand and his father's. He wondered if his own hands would ever look like that.
“I- I don’t know how to change back,” Tanjiro admitted defeatly. His parents shared a worried glance.
“How- how did you change back the first time?” His father asked him. Tanjiro shrugged and pulled his hand back into the water.
“I don’t know. I pulled myself back into the boat and at some point, I shifted back. I wasn’t sure how or why but I did.”
“Would you be comfortable climbing into the boat?” His father asked. Tanjiro nodded hesitantly.
“I might need some help though,” He admitted. “It’s- It’s hard to get in without legs,”
“Without legs?” His mother asked. He looked down at himself and was met with his reflection on the dark water. The water. It was so dark out they couldn’t see the rest of him through the murky water.
“Oh, um,” He tried to figure out how to put this. “I- I have a tail. Like- like a long fishtail.” He pulled his arm out of the water and showed them his forearm. “It has the same kind of scales and fins as on the rest of my body,” He said trying to prepare them for this massive serpent-like tail he had where his very human legs should be. His mother nodded in acknowledgment she seemed distressed by the fact that her son might have a large tail instead of legs.
“You ready?” His father interrupted, as he adjusted his position to help Tanjiro out of the water. He closed his eyes and took a deep, cool breath through his gills. He opened his eyes and nodded to his father.
“I suppose,” he grabbed onto the side of the boat and his father moved in to hook his arms under Tanjiro’s armpits. Once his father had a hold of him he wrapped his arms around his father's shoulders. His father stood and lifted his torso out of the water.
The last time his father held him like this he was probably around three. It was his very first time out on the boat. He was scared of how much the boat rocked when he tried to get out so his father kneeled on the docks and scooped him up in a similar fashion.
With some effort, his father managed to step back and lay Tanjiro out on the floor of the boat.
There, for the second time now, Tanjiro lay in the moonlight with his new form completely exposed except this time his parents were there to bear witness to it.
His mother had let out a small gasp upon seeing his tail accompanied by his large dorsal fin.
He was lying on his side so as not to disturb the aforementioned fin with most of his tail hanging over the edge of the boat lazily drifting in the water next to them.
His parents were staring at him with that look again. He couldn’t blame them. If he ever came across a creature that looked like him he’d probably do the same, but it made him very self-conscious. He pulled the rest of his tail into the boat and wrapped it around itself.
He tried to shrink away and hide himself, but it was then that he noticed just how large he was. He had to be at least 13 to 14 feet tall. Tall? Long? He wasn’t sure. The only thing he knew was he was taking up way more space than he was used to. After a brief period of uncomfortable silence his father spoke up.
“Would you like to start heading back or would you like to wait a bit?” His father asked awkwardly. All Tanjiro wanted to do was shift back and curl up with his little siblings and go to sleep for the night, but he was stuck in this - this form.
“We can, but I- I don’t know if I’ll be back to normal by the time we’re back at the docks.” He told his father.
“That’s okay. We can wait with you as long as you like.” His father reassured him.
Tanjiro nodded in response. They all sat there in a thick fog of silence for a while. None of them knew what to do moving forward. They were just- waiting.
Slowly but surely Tanjiro began to recognize the sensation of his skin tightening as the transformation started to trigger. Tanjiro sat up.
“I- um, I think I’m gonna change back now.” He stated rather awkwardly. “Could- could you please look away again?”
In response, both his parents covered their eyes once more. Tanjiro also closed his eyes, not wanting to watch as his body twisted and contorted back into its human form. Once the transition was over he hurriedly threw his night clothes back on.
“Okay, I- it's over now,” Tanjiro said as he stood there awkwardly between his parents. His parents opened their eyes and he gave his parents a meek smile. It felt odd having his parents know. He could feel them looking through his human shell at what he really was.
His father cleared his throat.
“It’s starting to get late. We should start heading back now.” He said, picking up the oars. His mother moved over from where she was sitting and patted the spot next to her. He took it and rested his head on her shoulder. He listened to the wood of the boat groan under the rotation of the oars.
He was tired. Telling his parents about what had happened to him, about how he changed, emotionally exhausted him. Except, exhausted as he was, he was endlessly grateful that his parents had accepted him. He truly didn’t know what he would have done if his family had hated him.
“Thank you,” he whispered into his mother’s shoulder.
“For what darling?” His mother asked, reaching up to brush some of his hair out of his face.
“For still loving me despite-,” He hiccuped.
“Tanjiro!” His mother scolded, taking his face in her hands “Tanjiro, you are my son. My first child. I will always love you no matter what.” She said earnestly. She pulled him in and planted a soft kiss on the crown of his head.
He placed his head in her lap and she idly petted his hair. Tanjiro closed his eyes and listened to the clunking and slooshing of the oars pushing them over the water as he drifted into a peaceful sleep for the first time in days.
