Mitsuba Sousuke

Mitsuba (ミツバ), real name Mitsuba Sousuke (三葉惣助) is a ghost haunting Kamome Academy Middle School's lockers. He was a student at Kamome Academy's Middle School division and a member of the photography club before his death.

After being recreated by Tsukasa, he consumed the former School Mystery No.3's heart and is now the current representative of the 3rd School Mystery.

Appearance
Mitsuba is a slender and tall middle school-aged ghost with pink hair and eyes. He has a mole under his left eye.

He has medium-length hair with bangs that covers his right eye, and the back of his hair is usually tied up into a small ponytail, with hairpins holding it up. He wears a teal ear piercing on his left ear.

Mitsuba wears a yellow scarf with light brown stripes and a long-sleeved pink sweater over the Kamome Middle School division uniform, its sleeve always covering his right hand.

He has a scar on the back of his neck, presumably a mark from the accident that caused his death. It can be assumed that the burn marks on one side of his scarf and his (probably) missing right hand also resulted from the same incident.

Since his reappearance in Volume 6, he has been shown to have been gifted a new red scarf.

In his School Mystery No.3's clothes, he wears a tattered black jacket embellished with eyes over his regular clothes. His hair is speckled with black feathers. His red sneakers are changed into a pair of black boots with shackles attached to his right shoe. His remaining arm is replaced with a bird talon. His scarf is now red, with golden trinkets and a lock attached to it. The scarf extends into bony exoskeletons, which Mitsuba can use as appendages. Throughout the series, he has been repeatedly noted to have good looks, and Mitsuba himself acknowledges this. Although, the (now former) 3rd School Mystery remarked that he is only slightly above average in terms of looks.

Personality
Mitsuba is cocky, foul-mouthed, and very confident in himself, particularly his looks, and often brags about how cute he is. He has a tendency to call people by rude nicknames, and isn't afraid to throw insults. He knows how to get on people's good sides, and sometimes acts nice to someone if he needs to get on their good side. He has also been shown to be quick to cry, especially in threatening situations.

Due to his personality making him a target of bullying in elementary school, he created another, gentler personality in middle school to get along with others better. During this time, Mitsuba is nice, considerate, and friendly with everyone.

Despite being rude and loud, Mitsuba also has a more mellow side to him. He gets noticeably dispirited when talking about his past, gets lonely easily, and though he seems to have a hard time being honest (choosing to hurl harsh words instead), at times he is able to genuinely express happiness and kindness.

He is very fond of his camera and photography, almost to the point of obsession, according to Kou. He was a member of the school's photography club and had won several awards.

Low-Level Supernatural (Formerly)
Mitsuba is visible to the human eye, though distorted, when he grabs a person's hand and asks them if they know who he is at the school's lockers. In other circumstances, he is invisible to normal people except for those with supernatural affiliations, such as Kou.

"Bent-Neck Boy at the School Entrance" (Formerly)
In this form, Mitsuba seems to have lost all of his humanity. His body is made out of eyes and camera parts, loosely bound together with bandages, and has an exposed chest crevice. Instead of tears, black substances flow from his eyes and mouth. He uses his bandages to attack and wrap the victim.

He does not respond verbally to anyone and appears if he does not remember Kou. Yako later reminisced when her rumor was altered, she felt like herself, but as if a different side of her came out. It is possible Mitsuba still recognized his surroundings, yet could not answer to it.

Number 3's Powers
After consuming Number 3's heart, he becomes the School Mystery Number 3. He now has command over the Hell of Mirror boundary. The boundary and its arms now respond to his request, shown by how he is able to forcibly remove Nene and company from the boundary. With his new powers, Mitsuba is able to manifest in the Kamome Academy's mirrors. He is also able to access every reflection that was captured within those mirrors and used it to gain information on his past.

He uses his exoskeleton-like scarf as an extension of himself, utilising them as extra limbs. When he is overwhelmed with distress, the scarf moves involuntarily, attacking whoever he perceives as threatening.

Trivia

 * Mitsuba's favorite snack is flan pudding.
 * His biggest concern is that he can't build any muscles.