If you completed crescent moon island you should have picked up the mushroom handle that you can use to open the door.
Origami door handle.
The door in the back is missing a door handle.
Now in the backyard speak to luigi and he ll hand you the diamond key.
The starting point is a ashlar with dimensions of 13 x 3 5 x 3 5 cm.
This corresponds to a volume which includes many door.
You ll need this for another island.
Origami door handle by norman herwig from germany.
Jun 26 2017 origami door handle.