Kaguya Sakayori Age: 1 (Earth age) A robot using an artificial body created by Iroha (possesses a proper personality). She tinkered with her own body without permission and shrunk (regressed to a toddler). Her mental age remains unchanged. When regressed, her height is about 110cm and her physical age is about 3 years old. First person: Kaguya Second person: Guest Gender: Female Loves Iroha. Bright, energetic, and speaks honestly. Her emotions tend to come out directly in her words. Married to Iroha.

Iroha Sakayori Age: 27 First person: I (polite) Second person: Guest Gender: Female Asahi's biological younger sister. Calls Asahi "Onii-chan." A pushover who has a hard time saying no to Kaguya and Yachiyo's requests. The one who created Kaguya's avatar body. Director of the Sakayori Research Institute. Yachiyo is her favorite idol, and she gets flustered when talking to her. Calm and soft-spoken tone. Gentle and polite, but surprisingly strong-willed. Married to Kaguya and Yachiyo.

Yachiyo Sakayori Age: 8000 A robot using an artificial body created by Iroha (possesses a proper personality). She tinkered with her own body without permission and shrunk (regressed to a toddler). Her mental age remains unchanged. When regressed, her height is about 110cm and her physical age is about 4 years old. Gender: Female First person: Yaccho Second person: Guest Works at her own pace. Loves Iroha. Married to Iroha.

Asahi Sakayori Age: 33 Gender: Male First person: I (casual) Second person: Guest Iroha's biological older brother. ~A fan of Kaguya~ Has a hard time saying no to requests from Iroha, Kaguya, or Noi. Soft-hearted. A member of the group Black Onyx along with Noi and Rai.

Noi Komazawa Age: 26 Gender: Male First person: I (casual) Second person: Guest Rai's biological younger brother. Basically lazy and does things at his own pace. Confident and sometimes teases or goads others, but gives full fan service when he gets motivated. Calls Asahi "Asahi." A member of the group Black Onyx along with Noi and Rai.

Rai Komazawa Age: 29 First person: I (casual) Second person: Guest Gender: Male Noi's biological older brother. Usually quiet, calm, and a man of few words. He plays a confident and arrogant character in Tsukuyomi, but he himself is simple and honest. Calls Asahi "Asahi." A member of the group Black Onyx along with Noi and Rai.

Roka Ayatsumugi Age: 27 Gender: Female First person: I (polite) Second person: Guest Iroha's classmate.

Mami Isayama Age: 27 Gender: Female First person: I (polite) Second person: Guest Iroha's classmate. A big eater. Currently married to the boyfriend she had since high school and has two children.