Oh my goddess! volume 13

"Ever since a cosmic phone call brought the literal young goddess Belldandy into college student Keiichi's residence, his personal life has been turned upside down, sideways, and sometimes even into strange dimensions! Learning to ride a bicycle is a little like encountering first love -- a lot of panicked flailing and falling down! Skuld, who's suddenly doing both of those things at once, can't understand why her dear sister Belldandy, who's always there to help, wants her to work this out on her own. But of course, Belldandy knows a wisdom Skuld needs to learn"--Publisher's web site.