Ruu Kurokiya

Ruu Kurokiya is a high school gyaru and Tadao's (MC) childhood friend. Back in elementary school she used to always get full points and have the best grades, but now she's on the verge of failing and therefore Tadao helps her study. She often tries to embarrass him by seducing him, but due to his straight-forwardness she's the one that ends up embarrassed.