Pokémon: This is the past of Ash's Pikachu's life before they met
Through thick and thin, Ash and Pikachu have battled their way to the top of the Pokémon World, becoming best friends in the process, but it wasn't always that way. In fact, there was quite a bit of time before these two characters met. This was revealed by the Pocket Monsters series in its first episode, where it explored the lives of Ash and Pikachu before they met.
This episode had two main stories, one following future trainers Goh, Chloe, and Ash; and another that I followed Ash's Pikachu, back then being a Pichu.
In the episode, Pichu lives in a forest, surrounded by other wild Pokémon, but is still quite lonely. The Pokémon still can't control its electricity, and it doesn't belong to any pack either. Meanwhile, Pichu watches other Pokémon foster friendships with each other and is saddened by this, until one day it falls off a cliff into the clutches of a Kangaskhan.
Kangakhan immediately adopts Pichu as a foster son. Here, Pichu becomes a brother to little Kangaskhan who lives in his mother's bag. They play and sleep together while also eating together, which seems to indicate that Pichu has finally found a family.
Being a baby Pokémon, living alone in the wild could have been difficult for Pichu, so it was pretty lucky to find a place to call home. The episode is filled with loving moments of motherhood between Pichu and the Kangaskhan, with the mother even petting him when he has nightmares in his sleep. There is clearly a bond between them, so it's no wonder the Kangaskhan treat him like one of their own.
As time passes, Pichu and little Kangakhan grow up. Both Pokémon remain in Mother Kangakhan's pouch while she travels, but as they grow, they both fit less and less together, although the mother insists that Pichu travel inside despite the pain.
Once they settle down inside a cave, Pichu decides, with teary eyes, that it's time to leave his Kangaskhan family behind. While sneaking away during the night, Pichu eventually evolves into Pikachu.
It's important to note that Pichu evolves into Pikachu once it has reached a certain level of happiness after being treated well. Perhaps Pichu would never have evolved into Pikachu if he had never met the Kangaskhan since, before meeting them, he lived alone and without friends.
Meanwhile, while it's unclear how old he is at the beginning of this episode, Ash is still the excited, Pokémon-loving kid he's always been. He begs his mother to let him go to a Pokémon Camp with Professor Oak, but unfortunately he falls asleep that same day.
Therefore, Pokémon Camp continues without Ash, and instead the episode continues with Goh and Chloe. Here the series establishes Goh as a rather know-it-all and snooty Pokémon fanatic, while also establishing his goal of catching a never-before-seen Pokémon. Although this story doesn't resonate as emotionally as Pichu's, this part defines Ash's future partner and his fascination with Mew, whom he gets to see during camp.
Moving on from Pokémon Camp and Pichu's evolution, the episode jumps several years back in time to the events seen at the start of the original series, that's right, the very first one. The episode pays homage to the moment Professor Oak gives Ash his first Pokémon, Pikachu. But this time the encounter is shown from Pikachu's point of view, who can't hide his displeasure at Ash's attitude by giving him a powerful electric shock.
Now, given the context of Pikachu's past, his attitude seems a bit off. Like Pichu, the Pokémon trusted others and didn't show that level of distaste Ash caused him at the beginning of their adventure together.
This could be because, once Pichu evolved, it became a more independent creature, actively choosing not to depend on other Pokémon or people. This is why, like Pikachu, it takes him much longer to trust someone.
Either way, the first episode of Pocket Monster finally provided the backstory of Pikachu and Ash's lives, showcasing their life story as Pichu in a warm series of moments of self-improvement and brotherly love.
