Paper Mario/Chapter 5: Hot Hot Times on Lavalava Island

Hide and seek
You find the first Yoshi Kid in a bush. The red one is found first. But before that you should get Sushie on your party. When you are in Yoshi Village where everyone's going crazy, take the western exit. From there, there will be a full row of bushes blocking your entrance. Go to the center of that row and push. Swim west from there, and on the westernmost half of the next screen, go to the dock. Again, bushes will be in your way. The first one is just a gate and the second one is the key to getting the red.