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.

It's Kanna's sports festival. However, when she learns Miss Kobayashi is too busy at work to come, she sulks. Miss Kobayashi wonders why she'd want her to come so badly when she isn't Kanna's parent, but Kanna already views her as one. Even Takiya tells her, "You should decide based on if you want to go, not if you can go." Finally, the day of the sports festival arrives. As a dragon, Kanna should have overwhelming physical prowess, but...?!

On Valentine's Day, Tohru attempts to give Kobayashi some chocolates containing a love potion, but she quickly sees through her plan. However, Kobayashi ends up eating some of it after mistaking it for chocolate Kanna received, although the love potion gets cancelled out by some alcohol that was included in the chocolate. Later, Makoto invites everyone on a trip to a hot spring inn, where Tohru gives Kobayashi some regular chocolates.