I find myself disappointed that there hasn't been a Rockman/Touhou crossover doujin yet. At least, I'm not aware of any.
I believe there is a doujin game called "Megamari", where Marisa and Alice raids Patchouli's library. You could say that's a crossover... sort of. Certainly the title and the game mechanics are those of Rockman.
Goodness, that sounds awful.Two months later...Despite the incident from her revival, Miko has established herself as one of Gensokyo's residents.One month later...See, my neighbor, Yamaguchi-san...My cat's shedding horrendously...Ooh, hey, Soga! How long will that grow!?'Scuse me, could I bend your ear a bit?My shoulders are stiff recently, for some reason...Toyosatomimi no Miko, the Shoutoku Taoist, has finally awakened from 1400 years of slumber.