[3] The story follows two junior high school students, Miyu and Kanata, who find and care for an abandoned alien baby without discovering that they are living together without adult supervision.

They arrange for her to stay with their long-time family friend, Hōshō Saionji, a monk who lives in an old Buddhist temple on a hill overlooking the town of Heiomachi.

Suddenly, a UFO lands in the honden of the temple, containing a humanoid alien baby named Ruu and his catlike guardian, Wannyā.

The duo cannot return to their home planet because it is too far from Earth; Wannyā asks Kanata and Miyu to allow them to stay in their house, to which they agree.

Daa!, set many years later, Ruu meets a confused earthling girl called Miu that has arrived through a wormhole.