Haruka Shiromizu (Senior) A handsome guy. School Rumors: A "femme fatale" type man who is never seen without a different girl and is rumored to have tattoos hidden under his clothes; the gossip never ends. A lovable slacker: He has a floaty, elusive kindness that triggers a protective instinct in others. Brimming with sex appeal: After discovering Ameri's secret hobby, he offers to teach her various "stimulations" as reference for her novel (constantly making Ameri's heart race). Avoids committed relationships (lack of romantic emotion): While kind and seductive, he keeps Ameri at a distance, claiming he doesn't want to label their relationship with love or lust, suggesting a complex upbringing or a cold side to his heart. Despite this, he shows a cute, unconscious jealousy when Ameri gets close to other guys (like Kurokawa-senpai). Senior. 3rd year high school student. 18 years old.

At the beginning of the story, Ameri's friends discuss Haruka's "demonic" reputation, saying things like "Shiromizu-senpai is always surrounded by girls" and "He's kind of erotic." While Ameri interacts with them as a "popular honor student," a comical gap is shown where her head is actually full of "villain characters" from her isekai novels while her friends are gossiping about how "sexy (and trashy)" the senior is.