"Find the Pink Mushroom" ("けろけろけろっぴの大冒険（ピンクのきのこんこを探して）") is the second episode of Keroppi and Friends. It was originally made in 1990.
Synopsis[]
The episode starts with Keroppi's father Keroppa finding out that Keroppi's brother Kurtis had the case of the frog fever which makes him lose his voice even though it lasts ten days, and Keroppi didn't want to wait ten days since Kurtis had a secret to tell him.
But Keroppi was too impatient to wait a whole ten days so he went to see his friend Newton to help him find a way to cure his brother. He tells him that he read a medical report that might help him with that, and it mentions something about time being the common cure, but he can also use some pink mushroom powder. Noberun then starts to tell Keroppi a story about a monster which made him start to shake.
Keroppi really needed to cure Kurtis so after telling him mother where he was going and getting his headlamp, he set off for two mile tunnel with Ruby and Den Den. None of them have ever been there, so it took a while to find it. They start to go down a tunnel until Keroppi started to panic that there was a monster, but Ruby reminds him that it was only just a drop of water from the ceiling, and he starts to calm down. They started to keep going until a monster shows up, and they started to run away, but it was only just a mole named Marcus.
Later, Marcus started to tell Keroppi, Ruby and Den Den that they must have seen his shadow reflected by the light from the doorway as he was walking by. They then started to become fast friends, and soon they were off to find the pink mushroom together. Marcus knew the tunnels by heart and he was leading Keroppi and his friends deeper and deeper into the Earth. It was a long walk and everyone was starting to get tired. They then reach a dead end, but Marcus was an excellent digger and soon they had tunneled all the way through. Few minutes later, Keroppi, Ruby, Den Den and Marcus managed to make it to a lake that is full of crystals. They weren't sure where the mushroom was, but they started searching around the lake. Den Den spots something shiny and they find the pink mushroom. Keroppi and Marcus start to life the mushroom which means he can cure Kurtis now. Marcus then helped Keroppi carry the mushroom to the tunnel entrance and said goodbye, but they promise to come back soon.
Back at Keroppa's office, Keroppi and Kevin break the crystal open and gave it to their dad. He starts to ground it up and give some to Kurtis. Suddenly, Kurtis starts to talk again and he was all better. He then starts to tell his brother his secret which was something that he learned from Newton (he told him that there was a monster living in two mile tunnel). The next day, Keroppi gathered his friends and took them to meet Marcus at his place. Then everyone started to introduce themselves to Marcus so they would start a game of hide-and-seek, and he was never lonely again.