Episode Title:
Regret of... the Mabinogion.
Episode Description:
During a quiz, Yūta becomes curious about why Shinka would join the club. Rikka and Sanae bring Yūta to the clubroom, where they simulate a spell from a fake summoning circle. When Shinka arrives at the clubroom, Sanae realizes that a notebook called the Mabinogion has gone missing. Shinka then asks Yūta if she can go to his apartment on Sunday. Yūta attempts send Rikka and Sanae on a wild-goose chase on that day. As Shinka arrives at Yūta's apartment, she frantically ravishes his bedroom in search for the Mabinogion. After Yūta finds the Mabinogion, he soon discovers that it is a journal from her chūnibyō persona Mori Summer, which she tears into pieces from embarrassment. As Shinka burns the Mabinogion, she reveals that she joined the club just to get rid of it, but she is shocked to learn that Sanae has kept multiple copies. With Sanae refusing to believe that Shinka is the real Mori Summer, Yūta suggests that Shinka should appeal to Sanae's delusions on an overpass, but Shinka ultimately cracks under the pressure. Shinka reluctantly decides to stay in the club until she can finally destroy Sanae's evidence.
