Awakening her dormant abilities as a devil one day, Yuuko Yoshida aka Shadow Mistress Yuuko, is entrusted with the mission to defeat the Light clan's shrine maiden, a magical girl, by her ancestor Lilith. Yuuko meets magical girl Momo Chiyoda through her classmate Anri Sada, and challenges her to a duel, but loses quickly due to her lack of strength. Since then, Yuuko has struggled with her role as a devil and her duel with Momo, and borrowed help from her regularly. However, by a strange coincidence, Yuuko also weakens Momo by taking away her power to cooperate in protecting the peace of Tama city.
Episode 1
Yuko didn't have horns or a tail when she went to bed last night! Now her mom's revealing the deep dark secret their family's been hiding for generations — What's going on!?
Episode 2
Well... it's time for Yuko to murderize a magical girl... but not before she gets in some exercise and spends her allowance, of course.
Episode 3
Lilith contacts Yuko in her dreams with vital information she must remember. After all, Yuko needs all the help she can get! Say, why is Momo helping her anyways?
Episode 4
Wait a minute; there's a switch on the bottom of Yuko's ancestor statue. What happens if it's turned on? Later, Yuko needs cash fast cause she owes Momo A LOT of money!
Episode 5
Momo finally meets Ryoko. Later, the accident-prone Yuko must carry a FRAGILE and VALUABLE laptop home with her. What could possibly go wrong?
Episode 6
Yuko will need to go deeper into Momo's subconscious so she can implant the idea that will change everything! Perhaps compassion can triumph where fighting has failed.
Episode 7
A change of fortune can only mean one thing: FOOD! Later, Yuko learns the hard way that she and Momo have vastly different definitions of “training.”
Episode 8
Mikan finally makes her debut, and Yuko's anxiety spikes to even higher levels! Is the magical girl here to murderize Yuko or for another reason?
Episode 9
Yuko and Momo finally resume their duel. In the end, there can be only one winner — who will receive the higher exam score? Later, Mikan takes Yuko to a zombie horror movie.
Episode 10
Look out Yuko, Shion's up to something... and she won't rest until she runs her experiments! Then, can Yuko and Momo keep a secret from Ryoko?
Episode 11
Yuko's worried about Momo and dives into her dreams again to get the magical girl to open up. However, is that a good idea? Who knows what could happen this time.
Episode 12
Momo needs to process the shocking revelations that rocked her to the core! Perhaps Yuko can solve the dilemma by offering Momo a deal with a demon girl.
