Erimi Mushibami, a scion of the Hundred Devouring Families’ Mushibami branch, inherits her lineage’s expertise in psychological and physical torture, channeling it into high-stakes gambling rigged with tools like the "Finger-Cutting Guillotine." Petite and doll-like, her striking bi-colored eyes—dark pink paired with indigo or violet—peer beneath pink pigtails, while her Gothic Lolita attire contrasts with childishly whimsical accessories, notably a tattered stuffed caterpillar dubbed "Imomusshy-kun."
She joins a faction plotting to overthrow Kirari Momobami, craving peer validation yet frequently dismissed for her juvenile antics and attachment to the plush. Though outwardly brash, her insecurity fuels reckless gambles, such as confronting Yumeko Jabami and Midari Ikishima in a thread-cutting guillotine match. Secretly equipping her device with a protective metal plate, her paranoia over its potential removal unravels her composure, culminating in a tearful retreat when she snatches her finger from the blade prematurely.
Her personality melds calculated cruelty with fragile insecurity. She relishes psychological domination, deriding others as "mobs," yet crumbles into fearful tears when threatened. This duality surfaces in contradictions: she coldly manipulates allies like Miyo Inbami during a rigged card game—prearranging hands until their scheme implodes—but also awkwardly comforts Midari after Yumeko’s dismissal.
During the student council election, Sumika Warakubami’s votes bolster her campaign, though Sumika’s backing stems from cynical amusement. Subsequent defeats, including a Rock Paper Scissors Poker loss to Yumeko, erode her confidence, yet Yumeko begrudgingly praises her tenacity and unyielding self-defined ethics.
Erimi’s arc flickers with introspection—regret after the guillotine gamble, strained efforts to reconcile her craving for respect with a terror of failure. Her dynamic with Midari veers between skittish avoidance and uneasy collaboration, while her inventive games, merging ancestral torture techniques with gambling theatrics, cement her family’s macabre legacy even as her personal ambitions falter.