One early morning, a large human-shaped object appeared in the mountains, spewing steam, before disappearing into the mountain fog. Sanae, Cirno, and Meiling all saw the mysterious thing. Sanae thought it might be a giant robot, Cirno was convinced it was a daidarabotchi, Meiling believed it was the Taisui Xingjun. Each of them set out to confront the mysterious thing. …

PROLOGUE 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.

After the events of Perfect Cherry Blossom, even though the cherry-blossom viewing season has passed, the residents of Gensokyo are gathering for feasts that occur once every few days. Each time there is a feast, a restless, spiritual aura slowly awakens. Three days before the next feast is to start, the girls of Gensokyo decide to look for the source …