Ep 36. Pikachu's Goodbye

In the season 1 episode 36 of Pokemon, titled "Pikachu's Goodbye," Ash, Misty, and Brock stumble upon a Pikachu paradise while headed to the Safari Zone. Here, they notice that all the Pikachu are having a great time playing with one another and living in harmony.

Suddenly, they spot Ash's Pikachu, who is hesitant to join in with the others and show his playful side. Ash is puzzled by this, as he's never seen Pikachu act this way before. However, Pikachu's unhappiness comes to light when the group witness another Pikachu trying to leave the paradise to be with his trainer.

Pikachu's experiences with Ash and his adventures have made him realize that he's happy with Ash and doesn't want to leave him. This realization leads to an emotional moment between Ash and Pikachu, with the monkey-like creature struggling with whether he should stay with Ash or leave to live with the other Pikachu.

Eventually, Pikachu makes an unexpected decision and decides to leave Ash and stay with the Pikachu paradise. Ash is devastated by this news, but after he sees Pikachu playing happily with the other Pikachu, he accepts the decision. Pikachu says goodbye to Ash, and the trainer knows it's the last time he'll see his friend.

The episode ends on an emotional note, with Ash walking away on his journey, while Pikachu stays in the paradise with his kind. It's a critical episode that showcases the bond between Ash and Pikachu and how important it is to have someone you can trust and care for.