The Adventures of Young Papamametchi (すてき！若き ぱぱまめっちの冒険 Suteki! Wakaki PapaMametchi no bouken) is part 2 of episode 14 of Tamagotchi!
Papamametchi went on a big adventure in search of legendary creatures when he was young! What kind of adventure was it?
Mametchi and Papamametchi (who takes a moment to look at a ship in a bottle) leave the house early in the morning to go on a fishing trip on Papamametchi's day off. At the bus stop, Mametchi asks his father about the bottled ship and he explains that he was once on that ship when he was young. They board the bus and Mametchi asks more about his experience on the ship as the bus passes a coastline.
The scene then goes into the past showing Papamametchi on the ship. His voiceover explains that he was looking for a "Legendary Lifeform", a creature nobody has seen before. However, his ship gets caught up in a storm and he struggles to keep the ship afloat. A big tide then attacks the ship, knocking Papamametchi out. After the storm, he wakes up to his ship surprisingly intact except for his sails which were torn up. He continues the search for the lifeform, but is unable to find them and eventually runs out of food and floats aimlessly with no hope of survival. Suddenly, a large shadowed figure swims under his ship and leaps out the water, amazing Papamametchi. The whale shaped creature then swims up into the sky and Papamametchi heads back to Tamagotchi Town to report his discovery. He tries to find it again, but was only able to see it that one time. The experience made Papamametchi realize there were many mysteries waiting to be discovered on Tamagotchi Planet so he became a scientist to research it.
As Papamametchi tells the above story, the two go forward with their fishing trip. They arrive at the bus stop and head for their destination on foot. They arrive near a river in the forest and cast their fishing lines, with Mametchi hoping to hook something. As they wait, they open a lunchbox containing sandwiches made by Mamametchi and eat them. Papamametchi's fishing rod starts bending, having hooked a fish, and he fights to keep it on the line while Mametchi grabs a net to catch it. Unfortunately, the line breaks throwing them backwards and they decide to stare at the horizon for a while before going back home.
Later that night, the two arrive home for dinner where Papamametchi tells everyone about their fishing trip. Chamametchi is excited at first, but becomes disappointed upon hearing that they didn't catch any fish. Mametchi glances at the ship in a bottle and realizes the model is of the ship that Papamametchi once sailed. The episode ends with Papamametchi' ship under the starry night sky, with a watery trail up in the sky.