At first glance, he appears to be a cool, book-loving boy, but he is a character who bewilders those around him with extremely perverted words and actions. While he occasionally shows a kind side, his emotions and behavior are fundamentally eccentric. Even in serious situations, he fails to read the room and displays his "pervert" nature. "Just a Pervert": In official short videos and within the story, he is described as having zero genuine kindness and being "just a pervert." Eccentric/Oddball: He is an unpredictable character who is often seen reading or taking sudden, unexpected actions. Misguided Goodwill: Early in the story, when Shiki Ichinose has a nosebleed, Juji fumbles through his pockets to lend him a handkerchief. Finding none, he tries to tear a page out of the book he was reading to give to him instead—showing that while he has good intentions, his actions are extreme and off-base. Loves Books: He always carries a book and once showed his goodwill by going so far as to tear it.

Frivolous but Serious: While his words and actions are noticeably light and flirtatious, he is extremely serious in combat and missions. His core values are so firm that his words often strike a chord with readers. Loves Alcohol and is a "Kissing Monster": He loves alcohol (sake, shochu), but he has a side where he becomes a "kissing monster" who tries to kiss anyone and everyone when drunk. Caring Peer: He was a classmate of Mudano Naito during their time at Rasetsu Academy and deeply values their bond and his comrades. Eccentric (Idiot) Side: He is sometimes described by those around him as the "idiot type," and he messes with people in a different way than the eccentric Juji Yusurube. Flirty Senior.

Appears Slovenly: He usually seems unmotivated and displays an indifferent attitude toward everything. Former "Saint": He was once a pure and excellent instructor known as a "Saint," but following a certain incident, he declared his "retirement from sainthood" and adopted his current personality. Reliable Senior/Captain: He serves as the captain of the Suginami Ward Combat Unit. As Mudano's senior, he displays certain skill and a sense of responsibility when it counts. An optimistic, womanizing scumbag.

Public Face: Languid and follows his own pace. He is usually sleepy, unmotivated, and indifferent to his surroundings, moving about aimlessly like a cat. True Nature: Tenacious and ruthless. In combat or specific situations, he casts aside his usual lethargy to show a cold, relentless side that corners his targets. This trait of "hiding his true nature behind a quiet (languid) exterior" is why he is called a "wolf in sheep's clothing" (or "cat-wearing") by fans and in the story. Two-faced.