Sora no Otoshimono

Synopsis

Tomoki finds a second Angeloid known as Beta-Class Nymph in his living room. The New World Discovery Club as well as the two Angeloids all go to the beach. Tomoki promises to go boating with Sohara, but neglects her in order to teach Ikaros how to properly swim. Sohara heads off by herself, thinking back to when Tomoki tried teaching her, but soon finds herself far from shore. Sohara falls overboard trying to retrieve her paddle, but fortunately Tomoki, assisted by Nymph, rescues her. Tomoki apologizes and Sohara forgives him, until he neglects her again to review swimming with Ikaros, which earns him karate chops. Later that night, Ikaros tells Tomoki how she does not sleep, and the two go back to the beach. Nymph follows them but is attacked by a group of delinquents. When Tomoki attempts to intervene, Ikaros stops the delinquents using her Angeloid abilities, causing them to flee.

(Source: Wikipedia)