After going back to the present Seiji learned that he and Hiiragi chan broke up before graduation because he was tired of her. He then leaped back to the past, and during lunch he absent-mindedly told her he was tired of karaage. She ran away in tears thinking he was talking about her and he realizes that this was the misunderstanding that caused them to break up, so he was able to patch things up.

So far, the biggest thing that has relevance is the fact that, he actually transitions back in forth between the present and future versions of himself in an attempt to change the future. At the moment, the two biggest reasons are to get Haruka's mother to accept their marriage. She is that standard high-class bitch that thinks unless the mc is someone "important" he's not good enough for her daughter. The second is to help Haruka's father. Her dad owns a fairly large company and in the future, it goes bankrupt. This, in turn, makes it so Haruka's sister needs to live with them, parents no longer live well, etc. In fact, him saving the company is his best bet to get Haruka's mom to accept their marriage.

At one point, Haruka's mom forced her to go on a date with some nasty ass son of a CEO for another big company. It all resolved with the help of Seiji and funnily enough, Haruka's dad. The worst thing that happened is he put his hands on her thighs rubbing them, but that's it. The second thing is, Seiji got amnesia for a little bit and his sister took advantage of it by saying they were in an incestual relationship.