Gensokyo is a fictional realm from the Touhou Project, a series of Japanese bullet hell games created by ZUN. It is a hidden world that exists alongside modern Japan, populated by various supernatural beings, including youkai, spirits, and magicians. The boundary between Gensokyo and the outside world is maintained by a magical barrier, allowing its unique culture and inhabitants to thrive away from human society. The setting of Gensokyo is characterized by its diverse landscapes, including forests, mountains, and villages. The inhabitants often engage in conflicts and events, which are central to the game's narratives. Key characters include Reimu Hakurei, the shrine maiden, and Marisa Kirisame, a powerful magician, who frequently interact with both friends and foes in this vibrant world.