Top 6 in Top 15 hot ecchi anime not for kids.
To Love-Ru - Trailer
The story revolves around the life of Yuuki Rito, a student who doesn't have the courage to confess his feelings to his classmate (or has failed every time he tries to confess), Haruna Sairenji. One day while Rito was soaking in the bathtub, a naked girl mysteriously appeared before his eyes. Her name is Lala and she is from the planet Deviluke, where she is the heir to the throne. Her father - King Deviluke - wants her to marry one of the candidates who are proposing to her and send her back to her home planet. But Lala decided to marry Rito and stay on Earth forever. Commander Zastin is ordered to bring Lala back and fight Rito unilaterally. He reports to his king that Rito would be suitable as Lala's fiancé, after hearing Rito, who is actually defending himself instead of Lala, say that marriage cannot come with only love from one side. Lala really loves Rito and decides to marry Rito after hearing him say that (against his intentions). Her father agrees that, if Rito can protect Lala, then he can marry her, but if Rito doesn't fulfill his mission and doesn't meet the king's expectations, he will kill Rito and destroy the Earth.