As Dai-sensei reports to Ayumu that Mystletainn will soon return home good as new, preparations begin for the school festival, with Haruna contributing her egg-cooking knowledge and Ayumu's class deciding to do a haunted café. On the day before the festival, Ayumu encounters a curious man who gives him a ring. After Ayumu spends the evening working on preparations with Taeko, he returns home to find that Mystletainnn has returned and uses it to remove everyone's memories of that unfortunate incident. However, to his misfortune, his classmates force him to crossdress anyway to advertise the café. Yuki asks Ayumu to accompany her in accordance to a letter she received, only to get hit by a prank and ends up summoning Mysticore again. The man from before appears, telling Ayumu to put the ring he received onto Yuki, which surpresses Mysticore so Yuki won't become a weapon anymore, although she mistakes it for a wedding ring when she wakes up. Just then, some Megalos appear in the culture festival, so Haruna, using a device to absorb some of Eucliwood's mana, transforms into a Masō-Shōjo alongside Ayumu in order to defeat them. Afterwards however, Haruna starts to experience an intense headache.