Ore no Kanojo no Uraomote: Pure Sweet Heart

It's the end of July and the summer holidays have begun. Takaya, the protagonist, has decided to announce his candidacy for the executive committee of the school festival. The president of the committee is Miyabi, his classmate he is attracted to. The day he thought the distance between them has diminished, he sees that there is something different in her. In the same period, the match of the basketball club of his younger sister Akeno has come near. And then there are Nazuki, his childhood friend, and Kanna, a girl he gets to know by chance. He feels that the summer of the last school festival he wanted to pass with his friends will be different. And finally, the second marriage of his father. It seems like that the spouse has a daughter. Is it ever possible that she is someone close to Takaya?