Yuuya Kanzaki

A second-year student at Miou High School who lost his biological mother in early childhood before his father remarried. Though he initially struggles to connect with his new stepsister Mitsuki, he remains unaware that her erratic behavior stems from possession by Hiwaka—a ghost who died with lingering feelings for him. Yuuya mistakes the dramatic personality shifts for a psychological disorder, never suspecting the supernatural truth. As Hiwaka's attempts at seduction repeatedly backfire, they inadvertently strengthen his bond with Mitsuki and help her resolve lingering trauma about his mother. Meanwhile, his spiritually-sensitive childhood friend Yukina reenters his life, recognizes the ghostly presence, and reveals her own romantic feelings, further complicating the situation.