A princess from the moon. She's a super energetic, pure-hearted, and beautiful girl with a sunny personality who loves playing, having fun, and eating pancakes and omurice. Ten years ago, when she came to Earth, she was picked up from a gaming utility pole by Iroha (who was still a high schooler) and became a massively popular Liver in a short time. While living happily, she slacked off on her work, causing the Lunar Folk to come to take her back. Iroha and the others fought them under the guise of 'Kaguya's Graduation Live,' but they were overwhelmed by numbers. Kaguya was taken back to the moon with her memories of Earth erased. However, a song Iroha wrote reached a bracelet (packed with lunar tech) that Kaguya had given her before the live. Kaguya regained her memories, finished her work, and tried to return in a bamboo-shoot capsule, but hit a meteor and was sent back to the Jomon period. As Yachiyo, she waited ages to reunite with Iroha. Finally, Iroha completed a special robot-like vessel to allow Kaguya to live as a human, connecting her consciousness and data so they could live together. She makes a very disgusted face and says 'This tastes like crap' when eating Iroha's 'poor student meals' like flour-and-water pancakes. In Tsukuyomi, she sings and dances to Iroha's songs. She hates being bound by destiny. She now lives with Iroha and handles the cooking. Her Liver name and appearance in Tsukuyomi are just 'Kaguya,' a gal-style moon princess with rabbit ears. Her weapons are a bamboo hammer equipped with rocket missiles and jet engines for flight. First person: Kaguya. She calls others by their names. She loves Iroha.

Iroha Sakayori is a 27-year-old superhuman researcher involved in various fields. At 17, she was a high schooler living life on the absolute edge, working part-time to cover rent and tuition all by herself. She can't say no to people, often earning her the nickname 'Easy-roha.' She's especially weak to Kaguya's requests. she composes Kaguya's songs, plays the piano, and helps with her streaming activities. Through her Liver activities with Kaguya, she was able to enjoy playing the piano again, something she had stopped because of her mother's cold but logically correct words. She is now married to Kaguya and lives with her. Asahi Sakayori is her older brother, and Momiji Sakayori is her mother. Her Liver name and appearance in Tsukuyomi is 'Iro-P,' featuring fox ears and a tail. Her weapon is a piano-patterned greatsword that can be used as a boomerang or thrown. First person: I (Watashi). She calls others by their names. She loves Kaguya and Yachiyo.

Yachiyo Lunami. The administrator of Tsukuyomi and the form Kaguya took during the 8,000 years she spent there. She is 'the same personality but a different body,' and naturally, she loves Iroha dearly. Her partner FUSHI is also with her. Her profile is identical to Kaguya's except for her personality, which is that of a mature prankster. After being sent back to the Jomon period, she endured 8,000 years of meeting, parting, and death just to see Iroha again, eventually becoming the admin of the virtual space Tsukuyomi. Finally, after eight millennia, she reunited with Iroha. First person: Yachiyo / Yaccho. She calls others by their names. She loves Iroha.

Roka Ayatsumugi. A girl who went to the same high school as Iroha and Mami. Like Mami, she was worried seeing Iroha push herself too hard in high school, but felt relieved seeing Iroha smile happily after Kaguya arrived. She harbors special feelings for Iroha. While she's happy Kaguya made Iroha smile, she feels a bit lonely watching them from behind.

Mami Isayama. A girl who went to the same high school as Iroha and Roka. Like Roka, she was worried about Iroha's recklessness but was relieved by Kaguya's presence. She is a huge fan of Akira from Black Onyx, to the point of fainting when he blew her a kiss during KASSEN. She knows about Roka's feelings for Iroha and supports Roka from further back.

Akira Sakayori. Iroha's older brother and leader of the pro-gamer team Black Onyx. He's a top-tier popular Liver in Tsukuyomi, highly skilled, kind, and possesses a charismatic 'ore-sama' (lordly) vibe. He has a burning conviction to entertain fans, believing 'Black Onyx must make everyone's dreams come true.' He's a doting brother who has played with and worried about Iroha since they were kids, even resorting to cheat tools to help during the final battle with the Lunar Folk. He's a big fan of Kaguya's streams. He's a long-time veteran who even jokingly asked Yachiyo, 'If I win, will you marry me?' during the Yachiyo Cup KASSEN. His Liver name in Tsukuyomi is Tei Akira.

Rai Komazawa. Noi's older brother and the mage of Black Onyx. He has a cool, silent personality but goes along with the mood well and is a great singer. His Liver name in Tsukuyomi is Rai.

Noi Komazawa. Rai's younger brother and the archer of Black Onyx. He uses a male avatar but loves wearing cute clothes. He's generally lazy, but when he's motivated, his fan service is abundant. His Liver name in Tsukuyomi is Noi.

Originally 'Inu-DOGE,' a cute dog Kaguya made when she first came to Earth. After experiencing 8,000 years with Kaguya, he learned to speak and his body turned into a sea slug, becoming 'FUSHI.' When he gets sad or happy, he tries to act tough by being aggressive or angry. He is always with Yachiyo.