Aoi was raised as a normal boy on Earth. Little did he know he was the heir apparent to Mito, the Queen-turned-Space-Pirate of an alien race that chooses their sex at puberty! Aoi fell in love with Mutsuki, the police officer who was chasing Mito, and the three of them saved the Universe. The only side effect was that Aoi blossomed into a beautiful young woman.

Now a malevolent entity calling herself the true Queen of the Universe appears with enough power to destroy entire planets. Aoi must defend her new throne, but she needs Mutsuki's help. Mutsuki must come to terms with her own feelings for Aoi so they can defend Earth together and become the galaxy's first royal pair of queens.

The story revolves around a girl named Yuuka, who encounters a being from the depths of the Earth named Chii-chan (a pun of chiteijin, the Japanese word for underground-dweller), and an alien named Ucchan (a pun of uchuujin or alien). The story follows their heartwarming and chaotic everyday lives together.

Set in an alternate version of the Meiji Era, a boy named Sakamoto Ryunosuke returns to Kyoto from Shanghai with his monster (youkai) Nekomaru. The law states that in order to live freely with humans, a youkai must be liscensed. The Kidou Shinsengumi Co. Ltd. is responsible for the capture of unliscensed youkais but must fight with the Tsubamegumi, who resents the new law. It turns out that Ryunosuke is the son of the owner of the Shinsengumis.

AD. 2023, Tokyo. Because of the change of the society such as internationalization and enlargement of the trading, the dark side of the society also continues changing. The criminals are getting deep, and their organizations are increasing its size, then the peace and security is getting worse. The government takes it seriously, and decides to introduce an innovative system. In order to cope with the special criminals, an extralegal police is founded. It is a special criminal team, Warriors, which consists of a few elite members. (Source: AnimeNfo)