university amateur sumo champion
Title given to the winner of the All Japan University Sumo Championship or similar collegiate tournaments. Not a professional yokozuna rank.
He became the university amateur sumo champion during his college days.
He used his experience as a university amateur champion to become a professional sumo wrestler.
横綱 is the highest professional sumo rank; 学生横綱 is an amateur collegiate title, not a professional rank.
Compound of 学生 (university student) and 横綱 (yokozuna, the highest sumo rank), referring to the top amateur sumo wrestler in university competitions.