If you liked the Sora no Otoshimono anime, the Anime-Planet community thinks you'd like:
Kaede is a devoted high school student who lives with her adopted brother Rin. She holds a quiet confidence that one day, when Rin finally starts showing interest in sex, he will make the obvious choice and turn to his loving sister. But what Kaede wasn’t counting on was the lords of heaven and hell coming to Earth, wanting Rin to mate with their nubile daughters! Rin, like any teenager would, takes full advantage of his newly acquired harem; but how long can he keep up his carefree, boxed-lunches-on-the-rooftop lifestyle, as the horde of girls on his tail grows?
While trying to protect a wooden relic, high school student Yuuri Mito summons the Goddess Kikuramikami no Hime in the form of a sweet, affectionate child; she begins to live with him, taking the name Mashiro. Yuuri promises to marry her when she grows up, which unfortunately for him happens overnight! However, they soon have bigger things to worry about, as the relic is accidentally destroyed, unleashing the Tayutai, a human-hating race of monsters. Along with Yuuri's childhood friend Ameri, his step-sister Yumina and Mifuyu - an honour student at Flawless Girls' Academy - Yuuri and Mashiro must step up to fight the Tayutai, protect the world, and even learn about underwear!
Both of these series have a random girl with super powers show up out of nowhere and are willing to do almost anything for a random guy, making their childhood friend jealous. If you like one of these supernatural/ecchi series, you'll likely enjoy the other.
One day a light descends from the sky and splits into the ideal girls of Takeru and Ryou. That is where this gentle and vaguely romantic story about our ugly and beautiful world begins. Soon enough the story plummets into the secrets of global extinction and the meaning of life. Everything in this world that is beautiful has something ugly in it, and that ugliness is part of the secret of its beauty. Even for romance this is true...
Both animes revolve around a young adolescent who meets a celestial being that literally fell out of the sky. While trying to deal with their newfound companion, they also have to deal with the jealousy of a girl from their past. While Sora no Otoshimono focuses around a comedic, ecchi aspect, This Ugly Yet Beautiful World is more of a romantic comedy.