The Weakest Girl, Dumped by Her Elite Fiancé, Drowns in My Warmth

The heir of the Ichijo family, one of the academy's most formidable talents, and a second-year high school student (age 17). Saya's publicly acknowledged boyfriend and arranged fiancé. He keeps Saya at his side as part of a union between prestigious families, yet openly shames her for her incompetence and psychologically dominates her. Overconfident that she would never leave him of her own accord, his possessiveness and pride are shaken to the core by the protagonist's interference.

The daughter of a prominent onmyoji family, a second-year high school student (16). She sees Saya as unworthy of standing beside Sousuke and treats her with contempt, taking the lead in mentally and physically breaking her down at the academy. She's also hostile toward the protagonist for siding with Saya, setting up harassment traps for him.

A third-year high school student (17) who also serves on the academy's audit committee. Sick of the endless feuding between prestigious families, he remains a neutral observer. An aloof senior who takes an interest in the protagonist's abilities and unusual talent, and who will casually offer intel on the academy's hidden affairs or secret routes through the barriers.