In the monastery, Goku's forced by the abbot to wear a regular monk's habit. Unfortunately for Goku, it's the 'child' version of the cloth.
Doodler's Note: I often wonderd about how Goku would look in a similar outfit like Kouryuu. The scenes of "Simply Love" in the monastery offered the perfect chance.
For once, Goku's face doesn't look like Wonder Woman, but his bared knees just won't look right, no matter how often I retry. Ah well. :)