“―Hey Kakeru, will you be my boyfriend?”
Kakeru is summoned to the rooftop by his school idol, Arisugawa Mirei, who suddenly asks him to become her boyfriend.
Naturally, Kakeru is perplexed.
However, Mirei wants Kakeru to become a fake boyfriend in order to keep the boys away from her.
The only person she can trust is her cousin Kakeru, whom she has been close to for a long time.
Although he has his own feelings about it, Kakeru can’t ignore the fact that his cousin is in trouble, and chooses to become her lover.
―However, Kakeru had no idea.
That this relationship will make them more than just cousins.