Requirements: Must be 310 days old.

First, go to the dojo which is located at the upper right part of the mountains then stay on one place, don’t move or even walk for 30 minutes. The max time limit for idles is 10 minutes, to extend the time simply talk, dance or throw snowballs. After that, you will be able to see three penguins with blue and black bands then they will ask you if you want to be a ninja, do this quickly or you will miss the chance to be one