Ruri G貴志
A second-year student at Tokioka Academy and the school's Vice President, Ruri maintains an impeccable public image—she's prim, proper, and genuinely committed to upholding school discipline and moral standards. At least that's what everyone sees.
Behind closed doors (and sometimes literally in the streets), she's a completely different person. Known as "The Blue in the Snow Field," her alter ego is foul-mouthed, uninhibited, and deliberately provocative. She's known for wandering around barely clothed—little more than panties on her head and a smock over her naked body—as a form of obscene protest against the oppressively strict moral codes that govern her society. Where her school self enforces rules, her alter ego actively rebels against them, staging crude acts of "terrorism" in response to a culture that's outlawed dirty jokes and toilet humor.
Only a handful of people know about this double life: Okuma was the first to discover her secret, followed later by Otome, Kosuri, and Hyouka. The contrast between her two identities is pretty much the entire point of her character.
In the anime adaptation, she goes by "Blue Snow."
Content compiled by AnimeList.moe from publicly available sources.