Takahata Masayoshi

Rumi's step-brother, a year younger than the protagonist. His frail constitution, slender build and pale skin make him look remarkably girlish. In love with his sister, in the past she caught him stealing her panties to use for dubious purposes and since then has been blackmailed into her service. He is now at her beck and call in her quest for sexual stimulation. He's still a virgin in all senses of the term, but is experienced in "petting level" play along with Natsuki and Rumi.