A Newbie Summary for the Main Touhou Games
Embodiment of the Scarlet Devil: A little vampire girl fills Gensokyo with a red mist so she can go outside during the day and it’s up to Reimu/Marisa to beat the crap out of her Chinese gatekeeper, librarian, maid, and eventually, her psychotic, basement-dwelling little sister and save the day.
Perfect Cherry Blossom: The heroines (now including Sakuya the maid) investigate an abnormally long winter and find that the Keeper of the Dead and administrator of the Netherworld is stealing the essence of Spring to feed a supernatural tree and make it bloom. Oh, she has a half-ghost samurai gardener too.
Imperishable Night: During a seemingly endless night, 4 teams (Reimu/Yukari, Marisa/Alice, vampire/maid, and PCB’s two antagonists) uncover the plot of the immortal Moon Princess to replace the moon with a fake one (?!), but not before beating the ever-living shit out of her nurse and two pet rabbits. They destroy a nice pair of pants afterwards to celebrate.
Phantasmagoria of Flower View: Spider lily flowers start blooming everywhere and rather than enjoying the view, everyone accuses each other of being the culprit, setting off a free-for-all. The perpetrator is a shinigami (death god) who fell asleep on the job and let souls pile up on the wrong side of the river of the dead. Her boss shows up to give everyone a talking-to, but our cast of brutes obviously doesn’t take kindly to that.
Mountain of Faith: Reimu hears there’s another miko in town and, ever the good sport, goes to trash the competition. She roughs up her rival and then picks a fight with her god.
Subterranean Animism: Reimu/Marisa head underground to Former Hell and find that a certain goddess from the last game has given the gift of nuclear power to a stupid raven. Said raven misinterprets the goddess’ wishes as an order to obliterate all life on the surface, so that’s no good.
Undefined Fantastic Object: While chasing down flying saucers, our heroines board a flying ship and look for treasure instead. They uncover a plot to resurrect a Buddhist nun who only wants racial harmony, but attack her anyway. Man, these chicks are evil.
Ten Desires: A Vocaloid Taoist prince (?!) and his/her nondescript friends come back to life. By the way, there’s a zombie. Just one. Little do they know that a storm of violence and exposed armpits is about to hit them.
The above was taken from Introduction to Touhou 8 - The Core Games and Story