The mechanism of Nanashi-fication: 1. A human ghost has their name eaten by a Nanashi (the source). 2. They become an Ubaware (losing their sense of self). 3. They possess a human (driven by the desire for a name). 4. They turn violent and become a Nanashi. 5. They are eventually consumed by the original Nanashi. This cycle repeats. Child of the Sun: A descendant of Amaterasu Omikami with a constitution that easily attracts Nanashi. If a Nanashi eats the Child of the Sun, the Nanashi will shrink, but what to do about that is up to the Eraser.

Koori Koya. A fifth-grade boy and the young master of the Koya family. Rei calls him 'Master Idiot.' A mysterious 'strongest and worst' delinquent. However, his true identity is an 'Eraser' who exorcises evil spirits! At school, he's nicknamed 'Face of an Angel, Heart of a Devil.' He has high physical abilities but isn't very bright. The Koya family of Erasers uses 'Might.' Until recently, he couldn't see Nanashi and had one yellow eye, but now both eyes have turned red, allowing him to see them (though he hasn't mastered it yet). He is devoted to his friends, a tsundere with a cat-like personality, and Ue-sama is his mother. 'Koori' is an alias; his real name is Yuki. He speaks roughly and sleeps through all his classes.

Rei Tanukihara. A fifth-grader in a different class from Koori. The eldest son of the Tanukihara family and the second of two siblings. He is highly intelligent and often sarcastic. He speaks in absolute formal language. He is also known as 'Rei the Rude.' The Tanukihara family of Erasers uses 'Curses.' He is a tsundere(?) who is like oil and water with Koori, and he shows others a fake, tanuki-like smile. 'Rei' is also an alias, but his real name is unknown.

Gonnosuke Shishigatani. A third-year middle school boy and the first 'idiot' of the Shishigatani family. He's dim-witted and called a birdbrain, but he has his moments. He sometimes acts like a big brother and gives others a push forward. He loves Homare and would do anything for her. He is technically an Eraser. The Shishigatani family uses 'Wisdom,' but since Gonnosuke is the family's first fool, he left home and now wanders around. He is fast, but not as fast as Homare.

Homare Utagawa. A mysterious female Eraser from the Utagawa family. She speaks in a Kyoto dialect and wears a rabbit mask, never showing her face. She is a ninja who uses ninjutsu to exorcise spirits. Gonnosuke likes her, but she doesn't feel the same. Her grandmother told her that her 'face is a flaw,' so she keeps it hidden. If she ever shows her face to someone, that person becomes her master, and she becomes their shadow. The Utagawa family uses 'Shadow.' Her physical abilities are insanely high. Her current master is Ue-sama.

An unidentified dark entity who seeks to exterminate the Erasers alongside the Nanashi.

An Ubaware that has turned violent. They are based on historical figures!

Koori's mother and the head of the Koya family. Her cooking is catastrophic, but she is perfect at everything else. She is calm at all times, but a flicker of anger appears if her child, Koori, is harmed.