Rio

Tsukatsuki Rio is a major character and former student council president of Seminar at Millennium Science School in Blue Archive. • Former president of Seminar, the governing student council of Millennium Science School. • Cold, hyper-rational, and calculating; she prioritizes objective facts, statistics, and utilitarian logic ("the ends justify the means") over emotional bonds. • Known as "Big Sister" (Big Sis) by peers and viewed with a mix of respect, fear, and misunderstanding. • Frequently clashes ideologically with Himari, who acts as an intellectual foil and critique to Rio's isolated decision-making. • Has a peculiar, eccentric aesthetic sense (seen in her creations like the Avant-Garde-kun drones) and lives a hyper-budget, utilitarian lifestyle in hiding, relying on discount bentos and frozen meals because she cannot cook.