"
K-11 is wall to protect from enemies that invade to Ichi Quadrant"
Ichi Quadrant also known as
1st Quadrant former known as
Alpha Quadrant is one of Quadrant System in
Touhou Galaxy,
K-11 is planet that defense space from ship entrance to Ichi Quadrant bypass from Shi Quadrant, and
Tomoya as defense from Ni Quadrant.