Welcome to Shibuya High School, a seemingly normal all-boys school at first glance - and it probably would be - if you weren't in it. You play as Hiro Matsui, a girl with too much time on her hands and is too bored with her life. So, what does she do? She decides to sneak into the nearest all-boys school just to see how it's like. This is where the story begins. Hiro meets two beautiful boys, Yuito and Masao. Is there something behind Yuito's cold glare? Something behind the knowing look in Masa's eyes? And who is the mysterious shadow lurking outside the gym at night?