Ah! It Doesn't Matter Where, So Long As We're Together!
Belldandy must spend a week without using her magical powers. Keiichi and the gang then get dumped on literally as all their friends and decide to store their things at the temple. Skuld creates a device that enlarges the storage room but when Keiichi and Belldandy use it, something goes wrong and they end up lost in a seemingly infinite space!
Aired 01/09/2006EP 20 - Ah! It Doesn't Matter Where, So Long As We're Together!

Oh! My Goddess: Flights of Fancy
The song may say "thank heaven for little girls", but who is college student Keiichi Morisato supposed to thank when three honest to goodness Goddesses move in and take over his life? After all, according to most mythologies, relationships between mortals and immortals usually leads to mortifying complications, so we're already talking about an extremely mixed blessing!
(Source: Crunchyroll)