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Shinjurō tried not to let his sigh turn into a groan as he pulled the damp sheets off Senjurō’s bed. Another night. Another load of soaked bedding and a crumpled pair of the boy’s academy uniform pants at the bottom of the hamper, the faint ammonia smell clinging stubbornly to the fabric.
The kid was already in his first year at Kimetsu Academy. He shouldn’t still be having accidents like this. Shinjurō had chalked it up to nerves, or maybe the stress of losing their mother so young, but the frequency was getting worse, not better. He rubbed the back of his neck, jaw tight.
On his way to the laundry room he paused outside Kyōjurō’s door. The eldest’s hamper was probably overflowing too. The eldest had always been so energetic. Even in his late twenties and working as a very enthusiastic history teacher at Kimetsu Academy, he almost always sweated through everything. He might as well go in and grab the hamper while he was already doing laundry.
The sight that greeted him upon entering the room left him stunned silent. Lying there on his stomach on Kyōjurō's floor was his youngest, pushing tiny toy cars around on the play rug with the printed roads. Right next to him sat Kyōjurō, cross-legged on the floor, making enthusiastic siren noises as he pushed around a toy fire truck.
For a long moment Shinjurō simply stood there. Kyōjurō, a grown man and respected teacher, looked up at him with the bright, innocent eyes of a child no older than six. Senjurō, barely aware of his father’s presence, made a small distressed sound and reached for his brother. The pieces clicked into place. The accidents. The secrecy. The way both boys sometimes seemed to shrink in on themselves after tough days.
They were regressing to cope with the trauma they had carried for years.
After that discovery, Shinjurō made a quiet decision. He understood now. The bedwetting and pants accidents were not just random failures. They were tied to the deep fear and sadness both sons carried. He started by gently introducing diapers for Senjurō at home. The boy was small for his age anyway, and the protection gave him visible relief. Even though Senjurō was in his first year at Kimetsu Academy, Shinjurō kept him in diapers during the day as well. It was practical. It was kinder.
Kyōjurō, when big, took his role as older brother seriously. As the history teacher at the same academy, he agreed to watch over Senjurō during school hours. Between classes he would check on the younger boy, change him if needed, and offer quiet comfort when Senjurō’s regression hovered close to the surface.
It was not always easy.
Some of the older students noticed when Senjurō needed help. Whispers followed him in the halls. A few cruel comments about diapers and babying slipped out during lunch or between periods. Senjurō, already sensitive, would tear up easily even when big. When he slipped into his little headspace, he became fully non-verbal, small and clingy, crying at the slightest frustration.
One ordinary afternoon the pressure finally broke.
Senjurō had been holding it together most of the day, but the bullying had worn him down. During a quiet moment between classes the accident happened. Warmth spread through his diaper, but the shame hit harder than usual. His mind slipped. The world grew too big, too loud. At barely three years old in his head, he could not speak. He could only cry.
Tears streamed down his face as he ran through the hallway, small hands clutching the hem of his uniform shirt. He burst straight into Kyōjurō’s classroom during a lively lesson on the Chuukoku-hen period.
The students fell silent. Kyōjurō, standing at the front with chalk still in hand, took one look at his sobbing little brother and froze. The sight of Senjurō’s tears, the wet uniform pants visible beneath the hem of his shirt, and the raw fear on the boy’s face triggered something deep inside him.
Kyōjurō’s shoulders trembled. His adult demeanor cracked. Within seconds he dropped to the floor and pulled Senjurō into his arms, his own eyes filling with tears. “Nooo… baby brother sad…” he whimpered, voice high and childlike. At six years old in his headspace, he rocked Senjurō gently, making soft shushing sounds even as his own tears fell. The two of them clung to each other on the classroom floor, a small island of regression amid the stunned teenagers.
Sanemi Shinazugawa, the sharp-tongued math teacher, happened to be walking past with a free period. He glanced through the open door, took in the scene, and immediately stepped inside. Without raising his voice he addressed the class. “Everyone stay seated. I’ll handle this.”
He pulled out his phone and called Shinjurō.
Shinjurō arrived within twenty minutes, face tight with worry. Sanemi met him at the classroom door and gave a respectful nod. “Your boys need you. I’ll cover Kyōjurō’s remaining classes today. Take them home.”
“Thank you,” Shinjurō said gruffly. He stepped inside and knelt beside his sons. Senjurō reached for him immediately with a broken sob, while Kyōjurō looked up with wet, hopeful eyes. “Papa…”
“I’ve got you both,” Shinjurō murmured. He lifted Senjurō into his arms, one hand supporting the boy’s padded bottom, and helped Kyōjurō stand on shaky legs. The drive home was quiet except for occasional sniffles.
Once inside the house, Shinjurō set about caring for them the way he wished he had done when they were truly small.
He ran a warm bath and gently cleaned both boys. Senjurō stayed deep in his three-year-old headspace, non-verbal and clingy, but he calmed under the steady touch. Kyōjurō, still regressed to six, chattered softly about fire trucks and how he would protect his baby brother. Shinjurō changed Senjurō into a fresh diaper and dressed both boys in soft, comfortable clothes suited for little ones.
In the living room he spread out the road play mat. He warmed two bottles of milk and sat on the couch while Kyōjurō and Senjurō drank, leaning against his sides. Later he prepared a simple dinner of soft foods and fed Senjurō small bites while Kyōjurō proudly tried to help.
When bedtime came, Shinjurō read them a story, voice low and steady. Senjurō curled up with a stuffed animal, already half asleep in his diaper and footed pajamas. Kyōjurō snuggled close on the other side, thumb tucked near his mouth.
As both boys drifted off, Shinjurō stayed there, one hand resting on each of them. The disappointment he once felt had faded. In its place was a quiet resolve. These were his sons. They had carried too much for too long. If regression and diapers and extra care were what they needed to feel safe, then he would give it to them without shame.
For the first time in years, the house felt warm. The embers of their little family were being tended with patience and love, and they would grow stronger for it.