The Illusionary Strawberry Underwear / Misunderstanding or a Wrong Guess?

While Manaka Junpei goes to his school's roof he bumps into a girl and see she is wearing strawberry panties, the girl runs away but leaves behind her a notebook. Manaka finds out that the notebook belongs to Aya Tojo, but he believes that the girl was Tsukasa Nishino the most popular girl in school and confess to her. After Tsukasa agrees she becomes Manaka's girlfriend. On their way home they talk about going to the same school and Manaka agrees. Manaka asks Aya to help him study so he will get accepted to the school he wants to go to.