77: Beyond the Milky Way

Tenryou International School divides its students into three groups by aptitude: Intelligence, Power, and Fate. Every year these groups hold a festival battle — each selects a girl and two supporters to fight for a young man who holds a special ring. This year the ring ends up on the main character's finger by accident. Now every faction's chosen girl has a reason to pursue him, and something about the school itself begins to feel wrong.