Koshiba is the only original Grey that regularly attends school. Koshiba can afford his Grey status, as he gets the nation's highest scores on exams. He has a sunny and outgoing character and decides to help Hina reform the school as the Grey's strategist. He claims his goal is to become a 'singing, dancing doctor'. He stole Hina's first kiss, became her best friend and falls in love with her.He had purple hair at the start of the manga but later bleached them blond
