>>9072936sorry i'll give a real answer, but it's not really easy to explain
first thing's first the first 5 games were sorta retconned out of canon. the sixth game is the start of the current setting. the only thing kept the same was the main two characters and a loose idea of the premise. the actual stuff was explained later in some of the print works and game plots
touhou takes place in a world of fantasy called gensokyo. the backstory is sometime in meiji era japan or something the spirits, gods, youkai and w/e mystical things found that they were losing their place in the world as humans grew more developed and had less faith and fear (something they needed to survive). so they decided they'd collectively use their powers to create an alternate world for them separate from the real world, where they and a small population of humans would live, able to survive by remaining hyper traditional (sorta)
reimu (the main character) is the shrine maiden of the hakurei shrine, a beat up shrine that lies on the "border" of gensokyo (it's not a physical border like a line on the map so it's hard to explain). her shrine sucks because no one comes to it. what she does is she's incredibly good at "exterminating" youkai (basically beating them senseless until they're pacified) and she resolves "incidents" (weird happenings that make up the specific plots of the games)
her friend marisa (the other main character) is a witch and also gets involved
alternatively, the plot is just pic related
that's essentially it, every game has its own specific plot. ZUN makes it all himself (all the main ones at least, a studio helps with some of the side games), all the art, coding, music, etc. the official art for touhou is trash but the gameplay and music is very good and the community makes up for his inability with a lot of fanart
