Summary for what happen so far:
Rito Yuuki is a high-school boy who can’t confess to the girl of his dreams, Haruna Sairenji. When he came home and lying in the bath-tub a mysterious, girl appears out of nowhere. Her name is Lala Satalin Deviluke and she comes from the planet Deviluke, where she is the heir to the throne. Her father (who is incidentally the emperor of the galaxy) wants her to return to her home planet so she can marry one of the husband candidates, but she bluff by saying that she wants to marry Rito in order for her not to go back.
Commander Zastin has been ordered to bring Lala back and battled Rito to ascertain his worthiness. He reports to the emperor that Rito would be suited to marry Lala, after hearing Rito say that marriage is impossible unless you marry the person you love (Rito was actually sick and tired and was telling his true feeling on the matter but Zastin and Lala thought he was saying his feeling of Lala). With this speech, Lala truly falls in love with Rito and decides that she wants to marry Rito. Her father decides that, if Rito is able to protect Lala from her fiancés, then he can be her fiancé, but if Rito cannot protect Lala from her other fiancés, Lala’s father will kill Rito and destroy Earth.
Things got wackier by the appearance of Ren Elsie Jewelria, Lala childhood friend. He still loves Lala and pursues her ardently. One of Lala suitor sends the galaxy most feared assassin after Rito. Lala manage to stop her (Yamigami) and Yami-chan develops a crush for Lala.
Several months later, Lala’s father comes to earth to tell her that Rito was officially chosen as her future husband, but Lala refuses to marry Rito, because she has noticed that Rito loves someone else. She decides to erase the memories of her from all people on Earth with one of her inventions, so she can start all over again on Earth. However, when waiting in front of school the next day, she finds out that her invention didn’t work and that everyone still knows her. Now, Lala, Rito and everyone begin a new year of high school as 2nd years. Lala finally realise that Rito loves somebody else but she say that she will try her best to win rito love…