Complex sentence: Nomura made her professional MMA debut with Jewels promotion on at the event "Jewels 7th Ring", where she defeated Yuko Kagoshima by technical submission after the referee stopped the fight when Nomura caught Kagoshima with an (armbar) in the second round.
Split into simpler sentences: Nomura made her professional MMA debut with the Jewels promotion on at "Jewels 7th Ring". She defeated Yuko Kagoshima by technical submission after the referee stopped the fight when Nomura caught Kagoshima with an armbar in the second round.