Oh My Goddess!, Volume 36 (Oh My Goddess! #225-230)

Ever since a cosmic phone call led five literal young goddesses - Belldandy, Urd, Skuld, and, like occasional vowels, Peorth and Lind - to live in college student Keiichi's residence, his personal life has been turned upside down, sideways, and sometimes even into strange dimensions!

Things go spectacularly wrong (as expected) when Urd and Skuld's rival schemes to help Megumi through a bad memory end up not only making her forget who she is, but making Keiichi and the goddesses forget who they are!