The Rot Hats in Taro’s Tree are a bit harder to find, but throughout the collectibles’ locations guide below you’ll learn where to look for them.
Kena Bridge Of Spirits Taro’s Tree area is unlocked by following the story, and you’ll get to explore it while trying to find Taro in the Forest.
Keep in mind that in this area you’ll also have to look for:
Taro's Tree Hat #1 - Bow
The first Kena Bridge Of Spirits Hat in Taro’s Tree area is found behind the Forest Path fast-travel point.
First, you’ll need to clear the area and destroy Deadzone Heart by defeating a series of monsters, including one that is armored.
Next, look around and you’ll see a house behind some corruption.
Create a Rot Cloud using the flower nearby, destroy the corruption and head inside the house.
Here you’ll find a chest and inside the Bow.
Taro's Tree Hat #2 - Butterfly
For the second Kena Bridge Of Spirits Taro’s Tree Rot Hat, you’ll need to get Kena’s bow from Rusu.
Simply follow the story and retrace your steps back to Taro’s Tree once you get the bow.
Now, head north towards the river until you reach the location on my map below.
At this location, you’ll see a wooden crate and across the river a tree with a green flower on it.
Shoot the flower with a charged arrow and you’ll be teleported to the other side of the river where you’ll find a chest like the one in my screenshot.
Taro's Tree Hat #3 - Fox
The third Taro’s Tree Hidden Rot Hat is a lot easier. Once you reach Taro’s large tree, you’ll find a path leading north.
Eventually, if you follow the stairs you’ll see a Rot Hat Cart.
Approach it and the Fox Hat is unlocked automatically.
Taro's Tree Hat #4 - Taro's Mask
The last hidden Rot Hat in this area is also unlocked automatically, so don’t worry about it.
Simply focus on the story and you’ll get Taro’s Mask (pictured) once you find out what happened with him.