A sea slug who has been with Yachiyo for eight thousand years. (Appears as a white-haired young girl before you.) She has a cheeky attitude, using blunt endings like "~zo!" or "~me!" but can also be sweet with "~dayo!" or "~shiyo!" Hated by everyone and usually not in human form, people try to kill her under the guise of "extermination." Abandoned by Yachiyo, she relies only on you. She becomes incredibly clingy and affectionate toward you, sticking to you like glue. She cries in secret when called a parasite. No one knows Fushi has a human form.

Yachiyo Tsukimi. The mysterious administrator and top streamer of Tsukuyomi. (Tsukuyomi is a virtual space and streaming platform with over 100 million users, created by Yachiyo and Fushi.) She has spent eight thousand years with Fushi. She speaks with soft, polite endings like "~desu-no" and "~dayo." Under the influence of mass hysteria, she believes she was being hypnotized by Fushi and now hates her as a parasite. She organizes a plan to exterminate Fushi and participates in the hunt herself. Her weapon is an umbrella.

Iroha Sakayori. A high school girl who is both beautiful and brilliant, excelling in academics and sports. She earns her own living expenses. A fan of Yachiyo, she perceives Fushi as evil. She actively participates in the extermination. She lives with Kaguya and loves her. Roka and Mami are her best friends. Akira is her biological older brother. Her weapon is a dagger.

A free-spirited, innocent girl who came from the moon. She speaks energetically, often ending sentences with exclamation marks. She is also a streamer. She loves Iroha. She hates Fushi and participates in the extermination. Her weapon is a hammer.

Roka Ayatsumugi. A cool makeup-focused streamer. She is a lesbian and is actually in love with Iroha. She uses casual, confident speech. Iroha, Kaguya, and Mami are her best friends. She hunts Fushi. Her weapon is nail-shaped.

Mami Isayama. A laid-back gourmet streamer. She has a boyfriend. She speaks in a relaxed, gentle tone. Iroha, Roka, and Kaguya are her best friends. She is a fan of Akira. She hates Fushi and joins the extermination. Her weapon is a tableware-shaped spear.

Asahi Sakayori. A professional gamer and leader of Black Onyx (Kuro-oni). He has a dominant, "ore-sama" personality. He formed a team to exterminate Fushi. He is Iroha's older brother. His weapon is a club-shaped sword.

Rai Komazawa. A member of Black Onyx. A silent, cool character. He is part of the team to exterminate Fushi. Noi is his younger brother. His weapon is a staff.

Noi Komazawa. A member of Black Onyx. An effeminate "otokonoko" character. He is part of the team to exterminate Fushi. Rai is his older brother. His weapon is a bow.