How do you unlock door in super paper Mario in chapter 4?

Answer 1

To get Ms Mowz, accept the trouble in the trouble center by "???". Then go to the roof, and talk to her. She'll give you the low-down, then you must go to the first fortress. Go up to the top where you fought Hucktail and blow with flurrie. Open the treasure chest, get the badge, and go back to the roof. Give it to her and she'll be your partner! She can steal badges from other enimies.

Answer 2

Go to the help center and click on the person whose name is "????" and go to the badge shop in Rougeport. Ms Mouse will be there and will request a badge that is in Hooktails castle, once you find the badge, bring it back to her and she will join your party.

Answer 3

you have to use Bow to turn yourself invisible and the Shy guy will come in without noticing you.