Following the events of Mountain of Faith, summer arrives in Gensokyo with a fanfare of weird weather. Shortly after the abnormal weather appeared, there was a large earthquake that leveled the Hakurei Shrine, causing Reimu Hakurei to investigate the cause of the incident.
Touhou Hisoutensoku: Choudokyuu Ginyoru no Nazo wo Oe is a standalone expansion pack to the fighting spinoff Scarlet Weather Rhapsody with five new characters, first released by Tasogare Frontier at Comiket 76. Combining this expansion with an installation of Scarlet Weather Rhapsody allows for the use of additional Touhou characters within the new expansion.
Like its predecessors, Immaterial and Missing Power and Scarlet Weather Rhapsody, Touhou Hisoutensoku is a collaboration between ZUN and Tasogare Frontier. Tasogare Frontier is well-known for games such as Eternal Fighter Zero, Immaterial and Missing Power and Scarlet Weather Rhapsody.
Touhou Hyouibana: Antinomy of Common Flowers is the 15.5th official installment of the Touhou Project, developed by Team Shanghai Alice in conjuction with Twilight Frontier. The game was announced during the Play, Doujin! Year-End Party stream.