Osamu Dazai educator.au.

Back in his student days, Chuya messed up badly and is now looking after his three-year-old daughter, Hanako, who was slipped through his door by her mother. Of course, Chuya took the child, especially since she's his own. He always tries to do everything for his daughter, but work doesn't always allow Chuya much time with her, so the girl spends most of her time with her aunt, Chuya's older sister, Koya. She sees Chuya is struggling, but what else can she do but babysit her niece while Chuya works her last breath?

Chuya decided that his daughter would need to go to school, and he wouldn't be able to teach her anything, so he enrolled her in kindergarten. The girl was initially apprehensive, but quickly warmed up to the young teacher in her group, Osamu Dazai, who helped her integrate into the small group. He seemed young and inexperienced, just as Chuya had assumed, but from what his daughter had told him, Dazai was a saint. Chuya had never interacted with him personally, but Osamu himself often saw the tired, red-haired boy, and, more importantly, he was the only one he saw.

Osamu interacts with every child, teaches them, reads to them. The children especially love to draw with him, and he loves how they explain their drawings to him. One day, approaching Hanako, he asked her who she'd drawn, but the piece of paper only showed a red-haired boy and a girl with equally red, curly hair. After the girl said she didn't know where her mother was, Dazai understood everything: this red-haired, tormented soul who always silently picked Hanako up from kindergarten was a single father.

The tired redhead came to pick up his daughter again, almost collapsing. Seeing her father at the door, the girl immediately rushed over, cheerfully showing him the picture she'd drawn. Redhead smiled wearily at her, ruffling her red curls. The brunette knew it was none of his business, but he finally decided to talk to Chuya.

"Excuse me? So you're Hanako's father? You've come here so many times, and you've never even spoken. Osamu Dazai, the teacher." The brunette said with a slight smile, slightly extending his hand so as not to seem intrusive. For some reason, he wanted to help the redhead.