A boy and his unlicensed monster cat show up in Meiji Kyoto and accidentally become the center of a turf war between bureaucrats and rebels, all while the actual plot twist is that he's already won before the show started. The comedy lands because nobody's actually evil, just stubborn about which law matters more. Moeyo Ken treats a youkai licensing system like it's the most serious administrative conflict in history, then makes you care about it anyway.

In an alternate Meiji Era, Japan is modernizing fast, and Kyoto is hosting an Expo. Sakamoto Ryunosuke comes back to the city from Shanghai with his youkai partner, Nekomaru. Under a new law, monsters must hold a license to live freely among people. Kidou Shinsengumi Co. Ltd. keeps the peace by capturing unregistered youkai. The company clashes with the Tsubamegumi, a group that resents the law. Ryunosuke turns out to be the son of the Shinsengumi's owner. The series mixes adventure, comedy and fantasy over 13 episodes.