Set in the fictional city of Sainan, the story of To Love Ru revolves around Rito Yuki, a shy and clumsy high-school student who cannot confess his love to the girl of his dreams, Haruna Sairenji. One day when sulking in the bathtub, a mysterious, naked devil-tailed girl appears out of nowhere. Her name is Lala Satalin Deviluke, the runaway crown princess of the planet Deviluke. Her father wants her to return home to marry one of her marriage candidates. When Devilukean commander Zastin arrives to bring her home, she swiftly declares she will marry Rito in order to stay on Earth, leading Zastin to attack Rito. But when Rito angrily declares that marriage is only possible with the person you love, the two dull-witted aliens misunderstand him, believing he truly understands Lala's feelings.

Lala quickly falls in love with him, and Zastin also approves of their engagement, much to Rito's dismay. While Zastin reports his support for the pair to Lala's father, Gid Lucion Deviluke, who is the King of Deviluke and much of the known universe, Rito reluctantly helps Lala transition to life on Earth, while gradually befriending his dream girl, Haruna, along with a colorful cast of other girls (both humans and aliens), such as the uptight, high-strung girl Yui Kotegawa, the gender-switching alien Run/Ren, and the queen bee Saki Tenjouin, among others. In the meantime, Rito must also fight off Lala's antagonistic alien suitors, one of whom sends the alien assassin Golden Darkness to kill him.

The story continues in To Love Ru Darkness, which focuses on Lala's little sister, Momo Belia Deviluke. She and her twin sister, Nana Astar Deviluke, have since come to live with Lala in Rito's house. While Rito remains indecisive between his longtime crush on Haruna and his growing affection for Lala, Momo has also fallen in love with Rito. But not wanting to steal Rito away from her sister, Momo instead plots to build a harem of girls around Rito, hoping that if Rito marries Lala and becomes the King of Deviluke, he can legally marry every girl who is in love with him, including Momo herself. While Momo works in the background and plays matchmaker with Rito, a plethora of beautiful girls gradually enter Rito's life and warm up to his kindness, including Golden Darkness, who has since lived peacefully on Earth but struggles to escape her dark past. Thus, Rito's otherworldly love troubles continue forever.

However, This anime has fallen off the production line, and we need to get it back on. There are still so many unanswered questions that the 4th season doesn't answer. I need your help to get this back up to speed, and I know that there are many others out there that agree with this and want a new season just as much as I do. If you have watched To Love Ru and enjoyed it, please sign to show the creators that we care and we want new episodes. If you haven't watched To Love Ru, watch it, and come back to sign the petition. This anime is beautiful, love-filled, and one of the greatest romance animes I have ever seen. I am calling out to you, the community, to help. I think, if we can all spread the word as efficiently as possible, we can get noticed, and get thousands of signatures. We can do it!