Due to the recent events that happened at the end of season 1, the Goddesses are having some stability problems with their body systems. The always adult-looking Urd becomes a little girl and has a fateful encounter with a boy, whereas little Skuld becomes an adult and wants to experiment adulthood together with Keiichi. 
 
Episodes 25 and 26 of Aa! Megami-sama! (TV) that aired separately from it's season 1 original broadcast.

Alone in his dorm on a Saturday night, Nekomi Tech’s Keiichi Morisato dials a wrong number that will change his life forever—reaching the Goddess Technical Help Line. Granted one wish by the charming young goddess Belldandy—a wish for anything in the world—Keiichi wishes she would stay with him always! Complications are bound to ensue from this; the immediate first being the new couple getting tossed out of the dorm—it’s males only! 
As the hapless student and his mysterious “foreign beauty” ride around looking for a new place to stay—risking the different dangers of seeking shelter with an otaku convinced Belldandy is an imaginary woman, and a Zen priest convinced she’s a sinister witch—Keiichi’s still got his classes on Monday morning! How is his new “exchange student” companion going to be received on the N.I.T. campus? A little too well for normal life to ever return... (Source: Dark Horse) 
Note: Won the Kodansha Manga Award for General Manga in 2009.

Keiichi Morisato is looking forward to university life. But in reality, he has no luck in anything, and he has trouble with clubs, love, etc. The truth is that he has an unlucky star above his head. One day, Keiichi is stuck watching the dorm while his sempai are away, and has a mountain of chores to do to boot. But Keiichi is a good-natured person, and is set about doing his duties. As he is about to finish his final chore, he makes a phone call to his sempai. But the words that came through the receiver are, 'Goddess Help Line.' Shortly afterwards, a beautiful goddess named Belldandy appears in front of him from the mirror of his room. 

Tags