Note: In short, most characters/entities in the story are categorized as "ikiryou" (living spirits) or "shiryou" (dead spirits) and then whatever subgroup they fall under. Humans, kami, and many youkai (including akuma and majin) are living spirits. Ghosts, shinigami, and shikigami are dead spirits. Kegare and noroi are not either; they are technically inanimate. Terms like Kaii, bakemono/obake, ayakashi, and mononoke are used interchangeably as catch-all terms for unknown entities. Junna's policy is not to go further than categorizing something as alive or dead while others, like Doikawa and the members of Doikawa-jinja, are attempting to create a comprehensive codex of anomalies that labels and categorize them.
Terms for supernatural entities:
- 怪異 Kaii (strangeness, mystery, oddity)/Youkai (apparitions) - this is the term used as a catch-all for any kind of supernatural being or incident (the kappa Squash is labled as a youkai, as are all other kappa)
- 死霊 Shiryou (dead spirit) - umbrella term for all dead spirits
- 怨霊 Onryou (vengeful ghost attached to a human) - a specific type of ghost that latches on to a living human (Ibuki is an onryou)
- 式神 Shikigami (familiar spirit) - a spirit created out of inanimate materials to serve the person who created it (the familiars created by the Isshiki family and Takara Tact are shikigami; Minami, Ryuuzaki, Yasutora, and Otonashi are also shikigami created by Ibuki)
- 死神 Shinigami (death god) - grim reaper-like figures that escort the souls of the dead to the underworld and act as messengers for Izanami-no-Mikoto (Inunaki and Yanagi are two shinigami that appear in-story)
- 幽霊 Yuurei/Yuuki/Yuukai (ghost) - terms used to refer to ghosts in general, usually they are stuck haunting a certain location; Junna considers them easier to mediate with
- あやかし Ayakashi (loosely, ghosts)
- 生霊 Ikiryou (living spirit) - umbrella term for all living spirits, humans, animals, plants, kami, and youkai included
- 人間 Ningen (human)
- 神 Kami (loosely, god or spirit) (Izanami, Benihime, and Doikawa-kamisama are all kami)
- 付喪神 Tsukumogami - youkai created from inanimate objects come to life, they are considered living spirits
- 物の怪 Mononoke (uncategorized anomaly, force of nature)
- 汚れ Kegare (impurity)
- 呪い Noroi (curse)
- 悪魔 Akuma (devil)
- 魔神 Majin (evil spirit)
- 化け物 Bakemono/Obake (monsters, specifically shapeshifters)
Links include kanji information from Tangorin; terms are loosely defined in general with context from their use in-story