If you're looking for manga similar to Oh! My Goddess: The Adventures of Mini-Goddess, you might like these titles.
Yanou Maya, an office worker who's tired of her boring but hectic everyday life, meets a weak, naive young god named “Rinjin-chan." This is the story of her daily life with a god, being gently bossed around and healed.
Koha-Ace stars Kohaku and features characters from various TYPE-MOON series. It is drawn in a super deformed style, and it is a self-aware series that constantly breaks the fourth wall.