One Room, Hi Atari Futsū, Tenshi Tsuki. (Japanese)
ワンルーム、日当たり普通、天使つき。 (Japanese)
Plot Summary: Shintaro Tokumitsu is a high schooler living all alone, but things take an unexpected turn when a girl named Towa shows up on his balcony. Not only is she incredibly pure and sweet, but there's something different about her-something...divine. (from manga)