Tsukatsuki Rio

Tsukatsuki Rio is a student at Millennium Science School in the game *Blue Archive*, formerly the president of Seminar and the main antagonist of Volume 2. Known for her cold and calculating nature, she prioritizes objective facts over emotions, creating tension with the contrasting Himari. Nicknamed "Big Sister" by her peers, Rio is unsociable and meticulous, never letting emotions sway her decisions, always sticking to the facts. She is determined to reach her goals, even if it means breaking rules. She has long black hair, red eyes, and fair skin. She secretly built the fortress city of Eridu and possesses advanced technological skills, creating weapons like the Abi-Eshuh power suit and the AMAS robots. She initially antagonized Aris due to a misunderstanding but ultimately acknowledges her mistake. Although initially portrayed as an antagonist, her true motives are to protect everyone from crises, even if it means being misunderstood. Through the main story, despite some extreme actions, Rio is eventually recognized by everyone for her quiet efforts to protect them.