Cool-headed but cares deeply for his comrades. Though he is unaware of it himself, his handwriting is catastrophic, and his drawing skills are equally poor. He is also a terrible cook, but again, he doesn't realize it. It's not that he's bad at taking care of others, but he isn't particularly good at it either. He often bickers with Rui, but it seems he trusts him when it counts.

Rui Mononoke. He has a strong sense of justice and is a hot-blooded man despite his appearance. For his rough speech and behavior, his gestures are surprisingly refined. He acknowledges and respects Jin, but he is by no means devoted to him; he is always looking for a chance to usurp him. Although not explicitly stated, he seems to come from a very high-class background (he might have been a young master). His upbringing shows in his piano playing and etiquette. His parents are apparently masters of flower arrangement, so he is knowledgeable about ikebana. Furthermore, while not to the extent of Seiichi Fumivake, he has a soft-hearted side and a personality that is easily liked by others.

He has a soft spot for Madoka and forgives her for almost anything. On the other hand, he is jealous of Seiichi, the Recorder and Madoka's childhood friend whom he idolizes. He speaks to him harshly and relentlessly, often requiring Madoka to intervene. He is quite versatile: he has been featured in sauna specialty magazines as a Sauna & Spa Professional, holds certifications as a Tea Specialist and Tea Meister, and has a column in "Weekly Tea." (Though he is often overshadowed by Seiichi). He can also cook and bake cakes. While not quite at the level of Madoka or Jin, he possesses high insight and observational skills, and even Sui Tou, the legendary Recorder, calls him "extremely excellent." Perhaps because he lost his family early, he is not good at being vulnerable or relying on others. He sometimes pushes himself too hard, and each time, Madoka scolds him and makes him rest.

He is terrified of ghosts and was the only one trembling when they went to a haunted house test of courage. Perhaps because he is so afraid of them, he encounters ghosts the most. Surprisingly clumsy, he is a beginner at cooking. Likely due to his long tenure as Koshiro's servant, he is very efficient. He is highly capable, performing tasks as if they were natural—such as flexibly predicting Koshiro's daily changing moods to provide appropriate meals and equipment—even before receiving instructions.

A crybaby, coward, and very lonely. Currently dependent on the twins. Due to his appearance, he is often seen as much younger than his actual age. Rui Mononoke has even had moments where he thought, "Is this guy really older than me?!" He also has a germophobic side. He can be a bit oblivious to the atmosphere at times. Is he attached to Jin Shiba? When children are involved in a case, he becomes quite merciless.

The one supporting Yukito Sumeragi. The older twin brother of Yunde Hoshikui. His hands are large and his fingers are long relative to his height. He possesses superhuman grip strength, capable of easily crushing an apple. He generally addresses people with "-san" (except for Yukito and Yunde). He is not combative, but when it's time to act, he has almost no hesitation. In truth, he has a bit of a cowardly side. He is somewhat overprotective of Yukito.

The one supporting Yukito Sumeragi. The younger twin brother of Mete Hoshikui. Though he has never studied it professionally, he has a natural talent for programming and worked as an underground engineer before joining. When comforting Yukito, he peels fruit skin extremely thin and feeds it to him on the tip of a knife. He goes at his own pace. He frequently disappears, making Yukito cry. He has little connection to conventional justice and has a combative side. He is skilled at knife throwing. He often goads others and maintains a provocative attitude. His curiosity about other Houses is quite high, and he frequently meddles with them.

A bright, positive, and hardworking person with an emotional and honest personality. A so-called "good guy" who always faces even the smallest incidents head-on. He is sociable, has many friends, and a wide network of acquaintances. He is well-liked by small children and the elderly alike. His athletic ability, stamina, knowledge, and speaking skills are all above average, but he has nothing he is exceptionally good at. If anything, his only superhuman trait is his sheer refusal to give up.

An unparalleled womanizer, but since he refuses to hit on students or those with partners, his success rate isn't high. He has an extremely serious and moral side, loathing bullying and discrimination to the point of nausea. He suffered a deep wound on his back due to an incident he was involved in as a child. He refuses surgery to remove the scar by his own choice. He says, "It's not a shameful wound I need to hide, after all." Because he lived in the countryside during his childhood, he speaks with a regional drawl. He isn't as frivolous as he looks, nor as carefree as he sounds; he's a problem child in many ways. He cares for his comrades and is a great cook. According to Daichi, he's "the type of handsome guy who wants to be seen as the comic relief." Seeing the character of Daichi Tenmei, he volunteered to be his Recorder. A womanizer, but a good man who values his friends. Actually left-handed.

He looks extraordinarily young and has an androgynous, beautiful appearance, often being mistaken for a woman. His long hair, which contributes to this misunderstanding, is grown out as a vow. A calm and pleasant young man. He is a hardcore fan of Daichi Tenmei and has looked after him since he was a baby. He fell in love with Daichi Tenmei's character as a human being.