藤沢 拓也

The protagonist of the story and the big brother of Chisato. He has recently finished his university years and is looking for a stable job in order to financially help his mother, who raises them alone. He currently works part time as a cashier in a supermarket not far from home. His mother relies a lot on him to take care of Chisato, because she is very busy with her work. He does everything possible to keep it on the right path, to such an extent that we can say that he has to assume the role of the father just for her but Chisato doesn't care and does a lot of nonsense.

He doesn't know how to reason her until one day: He decides to go to wash and accidentally meets Chisato (completely naked) in the bathroom. 

He had never seen his younger sister as a woman before, but seeing her femininity in all her splurter completely ignited her desire. Thinking about turning around, Chisato's haughty behavior makes him think that he's going to teach her a good lesson...

Over time, his feelings for his sister develop and evolve and he eventually falls in love with her so their relationship becomes a romantic relationship, but it can take three different turns depending on the route chosen./