This page offers a guide on grabbing the Secret Shine Sprite in Episode 6 of Noki Bay. This area is accessed by looking into the sun near the Shine Gate once you’ve collected 20 Shines back in Delfino Plaza.
Collect the Red Coins
Make a return to Episode 6: The Shell’s Secret and navigate back to the top of the series of ropes and back into the shell’s entrance to reach the secret course once more.
Head through the course until you reach the large red button and, upon using a Ground Pound, the Red Coins will materialize followed by a timer. Begin by using a Side Somersault to collect the 1st coin and then use a combination of a Side Somersault and the Hover Nozzle to reach the 2nd on the second moving platform here. Climb the pole to reach the next platform and then use a Wall Kick off the red wall to reach the 3rd coin.
Use the rope to reach the next platform and then turn around and climb the top of this red platform to reach the 4th coin at the end. Head back to the previous platform and Wall Kick to reach the 5th coin on the way up to the next platform.
Run straight forward and Wall Kick off the wall and hover over to the 6th coin before climbing to the next platform and using a Side Somersault to claim the 7th coin. Finally, head along the rotating wooden beam to find the 8th coin at the end, causing the secret Shine Sprite to appear at the end.