This Free Day

When the world is invaded, everything begins to undergo earth-shaking changes, and superpowers appear. Will you grow step by step? No! I want to get ahead of everyone else and be their instructor. What? You get a ring with a dead strong man inside. He teaches you powerful spells and makes you a strong man? No! I want to be the strong one, and I want to teach my disciples. "Aren't you the university teacher who complained about me? Come on, do three hundred push-ups for me." "Aren't you the young master who found the gangsters to bully me? Come on, you also do three hundred push-ups, no, squats." His girlfriend also became his student? It's okay, just take care of it secretly.