Bride of the Barrier Master Novel Volume 4 was written by Kureha.

Thanks to Saku's scheming, Hana and Hazuki's toxic parents are finally out of the picture. Now, the twin sisters can reconcile with their older brother, Yanagi. Finally able to enjoy a semblance of peace, Hana becomes more aware of her feelings toward Saku, but there's still an awkward distance between them. Welcome distraction arrives in the form of a collaborative school festival. All of the Obsidian High School campuses send a representative to compete against their fellow practitioners in some “friendly” competition. Because Hana's true strength was made common knowledge, she's unwillingly selected as a representative. Their biggest rival is Campus Four, which has claimed victory for the last several years. This event brings the Yotsukado clan's successor to the scene, and she obviously has it out for Hana. Meanwhile, the cult members who were arrested for breaking into the Association of Practitioners are under strict surveillance, but then they all suddenly die agonizing deaths…