When you defeat B.M., you normally see finished character art during the credits; however, if you defeat B.M. with a Super K.O., you'll see some original design and character concept art instead
Most websites say that all you have to do is win 6 matches with a Super K.O. and that is well...wrong. The actual way to get Honey's Nurse Outfits (ie her alternate costumes) is by having seen all 6 Super K.O.'s. There are different animations for the Super K.O.'s depending on the stage you do it in. You have to see all 6 different ones as well as beat the game in order to unlock Honey's new costumes.
The Super K.O.'s and where you can find them are listed below.
Super K.O. #1
Name: City Explosion
Where Found: Cross River Damsite/Old Armstone
Super K.O. #2
Name: Meteor
Where Found: Dark Royal Hanger & Deck, Neo Armstone City Tower, and Skies of Armstone
Super K.O. #3
Name: Tornado
Where Found: Serpent's Cage
Super K.O. #4
Name: Dinosaur
Where Found: Terror Furnace and Great Museum
Super K.O. #5
Name: Missile Command
Where Found: Marble Arena & Secret Chemical Plant
Super K.O. #6
Name: Lightning Strike
Where Found: The Great B.M.
In any round, when your enemy is close to death, just blow your armor (f,b,f,b,P+K+G) on his/ her face.
CAUTION:Your enemy must have only 5 points of live or less or it will take a minor damage.
In Arcade or Random Mode, finish Stage 7 in less than 5:50 with at least half your strength remaining or a Super K.O.
When you start a fight on loading screen push on controller UP, and don't relase button.Fight starts with different camera view. Works on all modes.
If you can defeat Kuhn in the bonus stage, B.M. will blow off his armor before his match with you.
In the options set the match count to 2 or higher. Win 30 interrupted (ie when a second player jumps in) matches in Arcade or Random mode with Honey. At the start of the 31st match do the armor break technique and win the round. At the start of the second round, Honey's skirt will be gone. This can be done numerous times after the 31st match provided you don't lose.
Note: this trick cannot be saved to the VMU and must be done over again if the DC is turned off.
In Arcade Mode, get to and defeat Mahler in under 5m50s with at least half your strength or with a Super K.O. (or Armor Removal), then defeat Kuhn in the Bonus Stage.