Trinity Seven volume 4 features story by Kenji Saito and art by Akinari Nao.

One of Trinity Seven's own members, the fiendish Liese, attacks Arata with a "passionate kiss" that purloins all of his magical powers! With the Demon Lord Candidate's magic in her possession, Liese's powers are unmatched. But the key to defeating Liese must lie with the Demon Lord Candidate Arata! What will happen when he's forced to undergo insanely tough training?!