Ataru Nishizono

He's Miku's sensei, a free loader at her house and her guardian when her mom got a job transfer to the southpole. He was in a relationship with Rin and also proposed to her, she said yes but attempted suicide a while after the engangement. He even told Miku that he didn't need anyone other than Rin in his life. But in the end i falls in love with Miku.