Growing up, Kasai only cared about one girl. His childhood friend, Haruhi. But Haruhi never really looked his way, and only thought of him as a friend. He spent his entire youth trying to be a guy she'd like. He dyed his hair, pierced his ears, picked up smoking, and did everything Haruhi said she liked in guys. he picked fights and refused to get along with others because she liked the "lone wolf" type. As such, he never learned how to talk to others. And he never enjoyed acting out this way. In reality, he just wanted to read books and study, and be a good normal kid. But Haruhi mattered more. It wasn't until he met the girlfriend of a fellow delinquent that his life began to change. Izumi, who was Kazuki's girlfriend at the time, was cute and honest, but held a facade, just like him. He connected with her and felt a need to protect her.. although he didn't know the true extent of her pain. Eventually, he was able to give up on Haruhi when he noticed his growing feelings for Izumi. But by that time, Kazuki had graduated and Kasai was left with no way to contact her. So he continued to work on himself and trying to put to rest the facade he created for Haruhi, although that task proved tougher than originally thought. Getting rid of the habits he formed as a "delinquent" was near impossible. But he was able to focus more on his reading and becoming more honest with those around him. He hoped by the time he met Izumi again, if he ever did, he could finally be honest with her.
Years after graduation, Kasai ran into Izumi again by coincidence. The two clicked immediately and started up their friendship again. Not after long, she was able to express to him the hardships she endured when she was with Kazuki. After finally learning the truth, Kasai decided he could become the strength she needed. He would become the support she needed back then, and help her heal. After some time, the two started to date, as the two were finally able to be honest with one another. Now they continue to support each other in their endeavor to heal and become the people that they want to be.
