as you know, I started to introduce some..."Danmaku" into our guild via the aggresors, gambling, and the new shrine
the girls are part of the touhou universe.
Well, what is touhou? It's a series of curtain fire shooting games or "Bullet hells"
EX of someone beating the extra boss in the game "Imperishable Night"
but, Touhou has a large following not just because of the game itself, but the music, characters and interesting universe
vocal remix of a song in Touhou 12-Unidentified Fantastic Object
random video I watched the other day (some jokes in the video are in-jokes for the touhou fandom while others are just odd ones)
there's even a few fanmade and spinoff games as well (The fighter game Scarlet Weather Rhapsody and fanmade game Touhoumon)
and with that...
http://touhou.wikia.com/wiki/Touhou_Wikigo here for more info