After receiving the password, you'll get a screen that says "To Be Continued", to avoid having to reset the game to get out of it, just hold A + Select on controller 1 and press Up on controller 2.
Whenever you are in a Blackjack match, hold B on controller 2 before dealing the cards to end the game after one match.
When you're in the bath house with Megumi, select the command "Take" and then choose "Megumi's Towel". After she finishes talking, wait 2 or 3 minutes and she will take her towel off.