|Base of Operations||Naraka High School|
|Translation||Change, Transform, Corpse|
|Seal location||Left Hand|
Momiji has fair skin, brown spiked up hair, and brown eyes. He is usually seen in the Naraka High School uniform. He is short for his age, and was even first mistaken for a middle schooler by Aira. His character is located on the back of his ballsack.
At the beginning of the series, Momiji stated that he wanted to change from being the person he was. He chose "hen", or 'change' as his character. His first attempt transformed him into a small plush penguin that Aira was carrying because of his fear of being killed during the blight. When in danger, Momiji transforms into a different person named Krishna. However, he has no memories of what goes on while he is Krishna. In addition, he has no knowledge of Krishna and cannot recall having ever met him. Since every ability or character needs great amount of concentration and imagination, it remains a mystery as to why he transforms into Krishna.
Later, Momiji discovers another way of using his ability. He can use it to change or transform one object into another by just imagining the object he desires. It is unknown if he can also change other people with his ability.
During the Kingdom arc, towards the end, during his duel with the fake Yama after his dream conversation with the real Yama, he gains a temporary ability to counter any character, and turns the 'Vengeance' blight unto itself, saving the entire school.
Since the first time he saw her, Momiji has had a crush on Aira, of which she is unaware. She was the first student from Naraka High School that he met, after she saved him from being run over. The two of them were placed in the same class and stayed together when the first blight occured. During that time, Momiji saved her from being eaten by instinctively transforming, which shows his desire to protect others, even if they had just recently met.
He and Aira are very close friends, and are willing to risk their lives for each other. This was shown when Aira attempted to kill Izuru for murdering Momiji. The two care very much about one another, and she is often seen around him, along with other fellow classmates and friends.
Hinata is Momiji's roommate. They are shown to be close friends, and Rokudou is probably the only one who can pierce Hinata's tsundereness.
Krishna is the person Momiji transforms into with his character when his life is in danger. Because of that, Momiji considers Krishna "his savior". Momiji, however, has no idea who Krishna is and is unable to transform into him at will.
Momiji appears to somewhat fear Krishna after Hinata tells him that Krishna had killed Tomonaga to take his heart and place it in him and is unsure of how to deal with him. He becomes more reluctant on relying entirely on Krishna for help in battles because he does not know what happens to him when he changes into Krishna.
However, he ultimately comes to rely on Krishna. During his battle with the fake Yama, after Krishna is killed, Momiji meets with the real Yama, and says later that he does not resent Krishna anymore.
After Bairi 'revives' Krishna by giving him her character, Hinata notes that the two are inseparable. Krishna takes 'advantage' of his form as a small child and monopolizes Momiji's time.
He lived together with his mother Beniko on the countryside. He loves his mother very much.
- Momoji grinds his teeth while he sleeps. Testing.