Oreshura

俺の彼女と幼なじみが修羅場すぎる

Eita Kidō has one goal: ace his exams, land a scholarship to medical school, and avoid romance entirely — an aversion born from his parents' messy divorce. When Masuzu Natsukawa, the school's most popular transfer student, discovers his embarrassing middle-school diary, she blackmails him into a fake relationship so she can fend off the constant confessions from male classmates. Their act convinces everyone except Eita's childhood friend Chiwa Harusaki, who has quietly liked him for years.