Ore no Kanojo to Osananajimi ga Shuraba Sugiru

Eita enters high school aiming for the National University School of Medicine. Because of his parents' divorce—and his goal—he shuns anything to do with romance or love. One day, Masuzu, the school beauty with the silver hair who's just returned to the country, enters his life in a most unexpected way. Chiwa, his childhood friend since elementary school, will not let this go without a fight.
Note: Includes volume 6.5.