Ground Defense Force! Mao-chan (陸上防衛隊まおちゃん Rikujō Bōetai Mao-chan), also known as Earth Defender! Mao-chan, is a 4-volume manga and 26-episode comedy anime, created by Ken Akamatsu.
On the edge of an invasion, the world's defense has fallen to unlikely straits due to the aliens being excessively cute. Due to combat engagements being televised: if the forces battling the aliens were not cute themselves the general public would revolt, as it would be seen as "bullying". Consequently, three military leaders chose their granddaughters, Mao, Misora and Sylvia, to be the defenders, fittingly, becoming a team even cuter than the aliens. The story follows the three eight-year-old girls as they try to defend the Earth against the invading aliens.
A game called Ground Defence Force Mao-chan was created and released on the 23rd of January, 2003, for the PlayStation 1 in Japan.
A "Raising Simulation" the player is tasked with raising Mao-chan as they would like to increase the Defence Cabinet's approval rating as she battles cute aliens intent on invading Earth.
Boasting 90 different abilities and the voices of the original cast from the anime, the player is given the opertunity to defend famous Japanese locations and to uncover over 10 alternate endings.
- Main article: Love Hina Cameo List
- Kagome Mishima bears a striking resemblance to Naru Narusegawa from Love Hina. The resemblance is noted upon in Episode 20 when they come face to face with that world’s Naru. The english voice actress of Naru also plays Kagome Mishima.
- The Japanese voice actress of Sylvia Maruyama also played Naru Narusegawa in Love Hina. This is noted when, when visiting the alternate version of Hinata House, she notes that it feels like she had known this place in an alternate life.
- Keinosuke Urashima/Keitaro Urashima appears as an alternate version of Keitaro Urashima from Love Hina. In this reality he has failed the Tokyo University entrance exam four times. Misora encounters him in the woods on Mt. Fuji in chapter 17 of the manga just as he is about to fail to commit suicide for the fourteenth time. Misora cheers him up just in time for him to receive 40 e-mail messages from the people who love him. Keinosuke mentions getting mail from his fiancée Nana, from Motoko and even from Tama-chan. His only appearance in the anime is Episode 24 on Mao's TV where Nana uses a "Naru Punch" on him. However, he is briefly mentioned by Naru in the Episode 20 preview.
- Nana Nanasegawa/Naru Narusegawa appears twice in the anime (once in ep 20, another in ep 25 on Mao's TV) as an alternate version of Naru Narusegawa from Love Hina. In this reality she has turned the Hinata House into an inn with her husband Keitaro, and is another victim of the cute aliens' shenanigans. In chapter 25 of the manga the Defense Force travels to Hinata Ryokan and are greeted by its proprietress Nana Nanasegawa and her fiancé Keinosuke Urashima. Based on the email she sent Keinosuke in chapter 17 she also possesses the same short temper seen in Love Hina.
- Carol Cameron's character design is based on Love Hina's Sarah McDougal
- Mayumi A. is the only operator named among the three Love Hina Motoko-look-alike operators.
- The Cosmic Tama-chan is a turtle-like Cute Alien who two years prior had been taken and cared for by a group of female Japanese Defense officers. Before leaving Cosmic Tama-chan laid four egg-like capsules. Three of which are the alien technology badges that is given to Mao-chan, Misora and Sylvie. The fourth egg contained a warning that Earth is targeted by Cute Aliens.
- Set in an alternate timeline from Akamatsu's other works, the series itself is rife with parodies and references, particularly to Akamatsu's earlier work Love Hina.