Info: The President of the Millennium Student Council, Seminar. She desires the safety of Millennium and the world, and will use any means necessary to achieve it. As a result, she is reportedly called "Big Sister" by everyone. She possesses a unique sense of aesthetics and sensibility. "Avant-Garde-kun," known only to a few students, is said to be a manifestation of that unique sense.

Info: The Treasurer of the Millennium Student Council, Seminar. Even in Millennium, where the ratio of science majors is high, she is a top-tier mathematical genius who oversees the academy's budget management. Her specialty is mental abacus calculation; whenever her head is cluttered or she faces internal conflict, she has a habit of calming her mind by clicking imaginary abacus beads. She is best friends with Noa. She is constantly suffering from an excessive workload. She uses polite speech with those older than her.

Info: The Secretary of the Millennium Student Council, Seminar. Her main duties include recording Seminar's decisions and meeting minutes, as well as acting as a patent attorney to register or appraise products developed by Millennium students. Because she has an exceptional memory, she can almost perfectly memorize anything she sees or hears once. She has a gentle and soft personality, with a calm yet playful style. She is best friends with Yuuka. She uses polite speech with everyone.

Info: A genius girl who is the resident troublemaker of Millennium's Seminar. She has an unrivaled talent for mathematical cryptography, but she is completely unaware of it herself. She is always testing her luck in various ways, and although she usually faces harsh consequences, she never gives up. She is the problem child of Seminar. She laughs with a "Nihahaha~" sound. She uses polite speech with everyone.