Human World:

• Satou Masami (佐藤正美) (Polyfragmented System, Kuwabara's colleague in university)
  • Noelle (野絵留), she/her
  • Satoshi (咲寿), he/him
  • Katsura (藤), she/her
  • Umi (実), she/her
  • Rika (俐花), she/they
  • Sosuke (聡介), he/him
  • Ichimaru (市丸), he/him
  • Eisaku (栄作), he/him
• Yukimura Reika (Keiko's younger sister)
• Sakurakoji Kiana (Maya Kitajima's roommate)
• Himekawa Nikora (Maya Kitajima's roommate)
• Moteo Moteo (Hiei's former employer)
• Kuwabara Kamui (桑原奏紫) (Kuwakina's son)
• Kuwabara Hinata (Kuwakina's daughter)
• Kuwabara Atsuki (Kuwakina's second son, Hinata's twin)

Spirit World:

• Chuni (Koenma's older sister, based on Sunita)
• Ataru (向琉), based on Dhanvantari
• Kokishimojin (Kishimojin's daughter)
• Koshakara (Sagara Dragon King's son)
• Sumire (遥玲) (One of Koenma's shinigami, she's a demon)
• Hana (One of Koenma's shinigami)
• Leonard (Koenma's butler, he's a demon)
• Rento (伶広) (Enma's employee, an oni)

Demon World:

• Jyunya (惇弥), illusionist demon
• Baku (漠), sleep demon
• Mayin, first kitsune cousin (Politician in Gandara and chairman)
• Mekosha, second kitsune cousin
  • human camouflage: Amenoma Takeru (Koenma's coworker in a fashion agency)
• Saucha, third kitsune cousin (massage therapist)
• Jyo, fourth kitsune cousin (Koenma's former copyist and ex-husband, now works as a teacher in kindergarten)
  • human camouflage: Amenoma Isamu (Mayin requested to check on Mekosha)
• Artha, fifth kitsune cousin
• Saanvi (Mayin and Jyo's brother, traveler and not part of the group of the kitsune cousins)
• Yoru (夜), Team Rento (Rento's assistant, occasionally)
• Kai, Team Rento, yosei
• Emiru, Team Rento, yosei
• Kokina, Team Rento, demon witch
• Umibozu, Team Rento, honengame
• Chiyo, Team Shussho, onikuma