イジワル方程式

Ijiwaru Houteishiki

For Mizuki, her life turned for the worst when her long-time neighbor and tormentor Ryohei joined her high school as a student teacher. Now she can't seem to catch a break from him in school nor at home! What can she do now that this sadist keeps leading her around, making her day to day life a living hell?! (Source: Mystic Iris)