Subaru Kujou is a naive and rich boy who fell in love at first sight with Aizawa-senpai who he saw by chance on the way to school.

Therefore, just like how he usually does with the power of his money, he gets his butler to send her all sorts of gifts, but she accepted none of it, which confuses him.
However, when he gathers his courage and personally invites her to his birthday party, she readily accepts; Her carrot-and-stick approach to him ruffles his heart.

The two of them slip away from the party and they end up by themselves in his room; Since it's his birthday, as a special occasion she'll give him what he desires as much as he wants...!?

(Source: DLsite garumani)