Seija Kishin is an amanojaku troublemaker who once caused an incident where she plotted to upturn the social hierarchy of Gensokyo. She prefers to always go against the prevalent ideas and opinions.
Amanojaku are one of the most well-known youkai in Japan. They are famous for playing pranks on humans and are often depicted as a small kind of oni that taunts people by perceiving their innermost thoughts. It is believed that amanojaku derived from the episode involving Amaterasu's envoy, Ame no Wakahiko, and her attendant, Ame no Sagume, in the kuni-yuzuri legend. In Buddhism, amanojaku are depicted as manifestations of carnal desires and evil intentions.
When you hear the name Ame no Sagume, chances are that a certain someone with a connection to Gensokyo comes to mind. Sagume Kishin is a goddess who lives on the moon and invites unfortunate slips of the tongue. Her ability to reverse a situation with her words is similar to Seija's ability to turn over anything, and considering the origins of amanojaku... it's natural to assume that they might have some kind of connection. However, if you ever ask one of them about it, you should be aware that the opposite of what they say could be true.
Capsule-Crazy Gensokyo
This history-defining fad that swept across Gensokyo came from the mind of a single amanojaku. Tricksters like Seija Kijin, who represent juxtaposing concepts such as good and evil, destruction and restoration, sage and fool, oni and human, and right and wrong, are often depicted in stories as the driving force that tears down the established order.
Seija designed and developed the Fabricated Maidens because she wanted to play pranks and harass people. However, her plan was thwarted thanks to Sagume's intervention. Collecting and battling with Fabricated Maidens became a fun and exciting pastime for all the denizens of Gensokyo... It's rather fitting that Seija's amanojaku plan resulted in the exact opposite of what she wanted.