Set in a near future, a time where robots are common workers for their owners. Takaya Murase has just purchased a maid robot from a robotic doll distriubutor, MaidWorks. Ready to live a normal cleaning, cooking, and serving life to her owner, Yui is purchased, by Takaya but he has other plans for her...like dressing her up in dress-costumes of his fantasies and more.

As far as it goes, many boys, especially in their teenage years, want to have a girlfriend. Keiki Kiryuu is no exception. One eventful afternoon, his days of yearning for a lover seem to come to an end when he receives a love letter from an anonymous sender—along with a pair of white panties. To determine the identity of his secret admirer, referred to as Cinderella, he proceeds to investigate several possible candidates including his senior Sayuki Tokihara, his underclassman Yuika Koga, and his classmate Mao Nanjou. However, as Keiki seeks to uncover who this mystery girl might be, he comes to know about the perverted fetishes hidden behind each candidate's innocent exteriors... [Written by MAL Rewrite]

The scene is Steam City, a London-ish city which represents an entire civilization run by coal and steam power. Because of steam, the city is sometimes covered in a mist. Villains take advantage of the steamy mist to hide and execute their evil plans. Only a few dare venture into what's beyond the steamy mist. They are known as the Steam Detectives: Narutaki (and his convertible all-purpose pistol), his nurse-assistant Lingling, and his Megamaton robot Gohliki. (Source: ANN)

Kumiko Ijima who is one of Nube's students recognizes that a man in a local park is really a criminal wanted for murder when she remembers drawing his face from the wanted photos posted by the police. Kumiko warns her classmate Kyoko while at the same time the man discovers the drawing with the name initials "K.I." written on Kumiko's drawing portfolio and briefly sees that Kumiko wears a red ribbon in her hair. The cops chase the criminal who crashes his car into a seal where a demon takes control over his soul. The demon is now on a killing rampage to find any girl that wears a red ribbon whose name initials are "K.I.". (Source: ANN)