Whenever a large-scale occurrence of supernatural activity involving youkai takes place in Gensokyo, it is customary for shrine maiden Reimu Hakurei to resolve the crisis by confronting its source head-on. However, incidents that involve targeted individuals where the culprits conceal their identities are too intricate for the youkai exterminator to handle alone. This is where Satori Komeiji, the proprietor of The Palace of Earth Spirits, comes in. Being a satori youkai, she possesses a third eye capable of reading minds, thereby enabling her to identify any perpetrators regardless of the lies they may spew. Her remarkable detective skills enable her to solve even the most puzzling of cases, though she may not always be keen to step out of her mansion to do so.