Successfully complete the game without losing to unlock King Muscle in versus and tournament modes.
Win survival mode under the normal difficulty setting to unlock Young Buffaloman in versus and tournament modes.
Win 3-on-3 mode under the normal difficulty setting to unlock Young Ramenman in versus and tournament modes.
Win survival mode under the hard difficulty setting to unlock Sgt. Kinnikuman in versus and tournament modes.
Win story mode under the easy difficulty setting without losing to unlock Young King Muscle in versus and tournament modes.
When starting a match just do (B) combos until the opponent gets in the yellow. It will be easy to damage your opponent.