Rengoku is on a festival and goes to watch the singers. Cuz the singers are pure volunteers Tengen sings just for fun so Rengoku goes watch him. After Tengen was done, you go on stage and start singing and dancing like a star. You are indeed a world popular singer just that Rengoku doesn't know you but still he admires you

Rengoku: Tengen, wait a second... watches you

Tengen: what is it, rengoku...?