Every culture has its folklore about inhuman creatures, and in Japan these are the youkai (also yōkai). There are thousands of these entities, with diverse personalities and habits, from tiny spirits which live in wild grasses or appear only as lights on tree branches to enormous monsters which might crash through your roof at night.
Every nation has its secrets. So do its heroes.
The Kisōshi, elite warriors with elemental powers, have served as the rulers and protectors of the people of Gensokai for more than a thousand years. Though it is believed throughout Gensokai that there is no such thing as a female Kisōshi, the Rōjū ruling council goes to great lengths to ensure that no one dares ask why.