Mizuho Kazami, a beautiful young woman, came to a high school in a mountainous area as a Japanese Language teacher; however, she is actually a representative sent by the Galaxy Association on a mission to observe the Earth. Her troubles start when Kei Kusanagi, one of her students, accidentally discovers her true identity. In order to keep her true identity a secret, Mizuho Kazami and Kei Kusanagi get married. Living together in secret, can they keep their relationship from Kei's classmates?

Onegai Teacher spanning through 13 episodes based on its manga (2 volumes) by Please!. This anime is a romance drama, with a sci-fiction theme and a touch of comedy. The anime takes the manga and expands it and adds more content to it.
The anime does have several laughs and comedic scenes which provide a good variation and also contrast between the romantic story, but at the same time is used to highlight the romance too. The first episode starts with a burst and keeps the viewer clinged onto the screen. The anime develops the relationship between Mizuho and Kei by the interaction of the supporting characters Koishi and Ichigo.