The Dog Island/Off to the Highlands

If you speak to Rode in his Dojo in Zoomy Village, he will tell you that it is time you saw Master Tao. But, to be his pupil, you need a pass, like you needed the Apprentice Ring to get to Rode.

Graduation Test
Rode will tell you to talk to the Sphinx in the South Sandy Desert. You need to find a Certificate and bring it back to Rode. First of all, you need to speak to the Sphinx.

He will tell you that a snake somewhere in the South Sandy Desert has a key, called the Ivory Key. The Sphinx will tell you to find it and bring it to him. The snake is on the west side of the desert, and when you've found which one it is, bark and it will drop the key. Go and talk to the Sphinx again.

The Sphinx will tell you to go and sniff a glow, which will appear not far from the snake who had the key. Go up to it, and shake the remote to dig. Bring the Certificate back to Rode.

Rode will thank you, and tell you that he will let Tao know you are coming. He then tells you that Tao's dojo is in Gola Highlands, which is across the bridge in Green Meadows.