Ichika is a female college student with a tomboyish personality who belongs to a motorcycle club. Surrounded entirely by guys, no one realizes she's actually a girl. However, she secretly has big tits and is a horny slut. One day, a friend enters her room to borrow the toilet and becomes instantly fixated on her huge breasts, visible through her sheer loungewear. When she suddenly lifts her clothes, he can't help but get turned on. Hidden beneath her everyday life lies an unexpectedly erotic side.