DAMEINU Reinaron
Complete | NADUKI Koujima | 2000 released
Shiro is a white dog god, who will turn into a dog when separated from Kiyoto and will vanish if Kiyoto no longer needs him. Kiyoto is a human, who is possessed by a black dog god. He feels guilty about his feelings for Shiro and this allows the black dog god to take over his body.
Boku, Ecchi na Tenshi desu!