Indian Summer, or Koharu Biyori in Japan, is a romantic comedy focusing on the lives of Takaya Murase and his robotic maid, Yui. Takaya has a hobby of collecting anime figurines and purchases Yui so that he can dress her up in whichever costumes his lewd mind can imagine, usually as a maid. Yui objects to this kind of treatment from her voyeuristic master, but it is her job to serve him as her programming dictates.
Throughout their ordeals, they meet many unique people, all with varying, yet interesting personalities. Their encounters help to make Takaya and Yui's experiences together all the more exciting.