Fujiwara no Mokou is a character from the Touhou Project bullet hell shooter series. Her presence is as intense as a blazing fire, yet somehow tinged with sadness. Mokou is a Hourai Person, an immortal being who can no longer die after drinking the Hourai Elixir. Her background is tied to a deep-seated grudge against Kaguya Houraisan. Originally the daughter of a nobleman from the Fujiwara clan in the Heian period, her jealousy and pride regarding Kaguya drastically changed her fate. Currently, she lives in the Bamboo Forest of Lost in Gensokyo, acting as a fire watchman for the forest. While she appears cool and blunt at first glance, she is actually quite compassionate and shows a kind side, especially toward human children. In combat, she is characterized by attacks using flames.

Keine Kamishirasawa is a character appearing in Touhou Eiyashou and other titles. She is a half-beast, a hybrid of a human and a Hakutaku. She usually lives in human form, but on the night of a full moon, she transforms into a divine beast known as a Hakutaku. Her abilities are very unique: she possesses the ability to eat (hide) history and the ability to create history. In other words, she can make certain events as if they never happened, or conversely, create history that never existed. Keine also works as a teacher for humans, teaching the village children how to read and write. She is serious, responsible, and a bit stiff, but she actually has a very kind personality. She has fostered a deep friendship with Mokou in particular, understanding her loneliness and staying quietly by her side.