After Mika's sister died, Mika falls in love with Jun, her sister's widower. And when she tells Jun that she will do anything to make him love her the way he used to love her sister, Jun holds her to her word.

Jun makes her wear a remote controlled vibrator attached to her clit so he can trigger an orgasm in her whenever he chooses. He takes her for walks outside strapped to a collar and leash and crawling on all fours like a dog. He invites a bunch of strangers from the Internet to gangbang her. And Mika does everything he asks, hoping upon hope that she can make Jun love her.

Pretty hot, particularly for a cartoon.