The headmaster's grimoire, Solomon's Gate, has activated. Even high level mages go crazy if they stare at it too long. Liese escapes battle with the headmaster, and attacks Arata and the others, where she uses her ultimate secret technique, Final Crest. And then, the school in the West falls when Liese freezes time...
Liese, the last Trinity Seven, appears in the Eternal Library bearing a demon lord seal, making her a demon lord candidate, as well. She tries to entice Arata to join the evil mage side to help save Hijiri, and kisses Arata while he's unsure what to do. Arata has his magic stolen from him, and Liese decides to attack the school.
The girls are running in their exercise outfits, with the boobs swaying to and fro. Arata's heart races. Everyone's having great time, and then a ghost appears in the library. Arata and the gang go to check it out, and are forcefully transported to the "Eternal Library". There they find the lost Trinity Seven!
It's summer. The gang's on a southern island, and there's cute girls in swimsuits abound. Arata's cooking yakisoba for some reason, but these things happen. The quartermaster is repairing the school that Arata destroyed in his collapse phenomenon. The girls enjoy a mixed-gender bath, and the demon lord candidate decides on a theme--control.
In order to become a mage, you need a research theme which archives one of the seven deadly sins. While thinking about what his theme will be, Arata and 3 others are locked in a barrier, with no exit to be found. But then Lilith and the others find themselves needing to use the restroom... Good luck, girls!