Karen Kohiruimaki, who has a complex about her tall height, takes up an interest in VR gaming, but ends up constantly panicking and logging out whenever her Llenn avatar turns out to be too tall or otherwise outrageous. After going through several games, Karen eventually tries Gun Gale Online and becomes delighted with the diminutive avatar that's generated for her, only to discover that the game she picked is one of gunfire and survival. Deciding to stick with the game anyway, Karen gradually improves her skill and updates her outfit to a pink color to suit her taste. Upon finding herself surrounded by other players, Llenn manages to defeat them using pink camouflage and high speed, quickly gaining a reputation as "The Pink Devil". Later, Llenn is befriended by another female player named Pitohui, who helps her pick out a new gun which she nicknames P-chan. Forming a squadron together, Pitohui makes a promise with Llenn that if she can manage to defeat her one day, they will meet each other in real life.