i first heard about touhou when i was frequenting smashfaqs (gamefaqs smash boards) due to people requesting for reimu to be added in smash, didn't really think much of her until i stumbled upon cirno's perfect math class which got me hooked on 2hu music and iosys stuff. Several mouths later + after learning about fumos, i finally decided to pick up the series by watching that one touhou introduction video on youtube and logging in moriyashrine.org.
by far the best thing that happened to me since picking up undertale and the my biggest regret is not joining the 2hu fandom sooner.