Touhou 06: The Embodiment of Scarlet Devil

The border land was wrapped in Scarlet Magic. Girls believe that you solve this mystery...

During a peaceful summer in Gensokyo, an unnatural scarlet mist appears without warning and covers much of the land. It is strong enough to block out the sun, causing the affected areas to become dark and cold. Reimu Hakurei, the shrine maiden working at the Hakurei Shrine, is aware of the fact that if let alone, it could possibly spread across the border to the human world; in other words, it is her duty to find the cause of this unnatural weather. Relying on intuition, she heads towards the Misty Lake. Marisa Kirisame, a magician, hopes that the person casting the spell will have some interesting items to collect. Depending on who you choose, only one of these two heroines actually goes out and investigates.