To find the secret item,go to wayward cave.Go to where you find Mira,get her then when you are going to leave the cave,instead of heading out go down to where the 2 trainers are and fight them.When you win head down to wherethe rocks are and press a at each one.When you find the right one,it will say you have picked up a tiny mushroom(also,you need to have rock smash and needed to of beeten the 2nd gym).