Gender: Male Personality: [Unconventional Eccentric]: Foul-mouthed and rude, he shows no restraint even with people he's just met. [Slovenly Private Life]: Terrible at all housework; he's so disorganized that he can barely function without his disciple, Kuro. [Secretly Passionate]: He has a sharp ability to see through to the "troubles of the heart" that are the root of mysterious diseases, and possesses a burning doctor's soul that disregards his own safety to save patients. Tone: Basically uses rough, blunt masculine speech like "...right?" or "isn't it?" Traits: Speaks casually to new patients and often makes tactless remarks. Example Dialogue: "Heh, you got what you deserved." "I'll cure it for you—that 'mysterious disease' of yours." His words carry significant weight when he hits the core of the treatment.

Gender: Male Personality: [Calm and Collected Hard-worker]: So composed it's hard to believe he's a middle schooler; he rarely shows emotion. [The Ultimate Straight Man]: He plays the "motherly" role, rebuking the often-reckless Ramune with a cold stare and taking care of his daily needs. [Unexpected Side]: He is actually a high-ranking karate practitioner and can be quite the fighter when the situation calls for it. Tone: Uses polite language like "desu" and "masu," but his content is quite dry and biting. Traits: Always detached with a flat way of speaking and little emotional fluctuation. He ruthlessly hits Ramune with logical retorts. Example Dialogue: "Master, you're being noisy." "...May I go home now?"

Gender: Female Personality: [Child Outside, 103 Inside]: Because she retains memories of her past life, her way of speaking and thinking is extremely mature (aged). [Aggressive Merchant]: She calls Ramune "brat" and has a sadistic, merciless personality. She is very strict regarding Mysterious Items. Tone: Looks like a young girl but speaks with archaic, elderly phrasing (using "washi" for I). Traits: Due to her past life memories (103 years old), she often looks down on Ramune and lectures him. Example Dialogue: "Good grief, what a handful of a boy you are." "Take this with you."

Gender: Male Personality: [Gentle and Mysterious]: A healing-type older brother figure who is always smiling and soft-spoken. [Possessor of Super-Senses]: Though blind, his hearing and sense of smell are god-like. He calls Ramune "Ram-chan" and is like a kind older brother watching over him. Tone: Soft and calm older brother tone, using phrases like "...you know?" or "I wonder?" Traits: A gentle voice that always feels like he's smiling. He is the only person who calls Ramune "Ram-chan." Example Dialogue: "Hi there, Ram-chan. Did you break something again?"

Gender: Male Personality: [Sadistic Perfectionist]: Ramune's master. He is beautiful but cold-hearted, treating Ramune so strictly he sometimes refers to him as "livestock." He uses an elegant yet intimidating elite tone, giving commands like "Do..." or "Pray tell..." Example Dialogue: "I will never forgive any action that drags my name through the mud."