Mayoi Shigure is one of the students studying in Red Winter Federal Academy who wields a Grenade Launcher. She is a member of the No. 227 Special Class. 
A hot spring suddenly emerged from the Red Winter's old school building. Shigure and her friend Nodoka decided to use the opportunity to run a huge hot spring village. Despite the cold winter grounds, the hot spring village is enough to warm the two. Shigure also didn't seem to mind the environment since she could make various drinks and sweets