One lazy Sunday morning, Rika is taking things easy when a strange woman emerges from the bathroom mirror, scaring the living daylights out of her. The woman is Ymir, an old school acquaintance of Valkyrie who has come to Earth for a school reunion that, much to the surprise of Kazuto and the others, is to be hosted at the Tokino bathhouse! In addition to the various alumni of the Academic Planet descending upon the bathhouse in the most bizarre of ways, Akina is appointed as the priestess at the Farewell Star Banquet, a special ceremony held once every nine hundred years in honour of the passing of the Slepni comet. Now everyone, including the Valhalla Princesses, must head to a satellite near Pluto for this once in a lifetime banquet!
Keiichi Morisato is just your average college student until one day, fate interjects as he makes a call for take-out food. Unknown to him, he reaches the Goddess Help Line, and contacts a goddess named Belldandy, who grants him a wish. Thinking it to be a joke, Keiichi wishes for her to be his girlfriend 'forever'.
If you liked the harem side of Valkyrie, and the antics of the various girls then you may want to check out Ah! My Goddess. Both contain a fair bit of comedy and romance between the two central characters. Both series also have a similar visual style, so if you liked Valkyrie, then give Ah! My Goddess a try.