One morning, as she left for work, she found a dragon before her. Stunned, the dragon transformed into a beautiful girl with horns, a tail, and a maid outfit right before Miss Kobayashi's eyes. Calling herself Tohru, this dragon-girl asked, "Please let me serve as your maid from now on!" Confused by her question, Miss Kobayashi remembered inviting the dragon into her home last night while drunk. She refuses, saying she can't afford to hire someone, but then she realizes she's almost late for work and--

Kanna starts living with Tohru and Miss Kobayashi. While the livelier residence is nice, sharing a tiny apartment with three people becomes cramped. So Miss Kobayashi decides to move. She winds up inviting Takiya to her new apartment for a party, but Tohru also invites her dragon friends, Fafnir, who lives in a cave, and Lucoa, who's lived in this world since ancient times, to visit their new home.

Miss Kobayashi and the others go to the beach. But Lucoa's immediately dragged off by one of the lifeguards for her overly skimpy swimsuit. After regrouping, they put sunscreen on each other, split a watermelon, go swimming together, and enjoy summer to the fullest. After the beach, it's comiket! Tohru and Miss Kobayashi both head for the otaku's battlefield, and even Tohru gets shivers from the incredible aura surrounding those otaku. While helping Takiya with his circle, Tohru's horns and wings are mistaken as cosplay?!

Tohru's now capable of handling the housework perfectly, and at Miss Kobayashi's request, she decides to make the best omurice for dinner one night. However, gathering high quality ingredients would put her over budget. Wanting to see Miss Kobayashi smile more than anything, Tohru ends up playing her forbidden card... Meanwhile, as Miss Kobayashi rides the train home, worn out from work, she dreams of the night she first met Tohru.