Since the hit anime series first aired, Pokémon has delighted viewers with light-hearted storylines, loveable characters, and all of the incredible creatures Ash Ketchum and his friends have encountered during their adventures.

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While most of the episodes over the past twenty years have shown the brightest moments of Ash's quest to become a Pokémon Champion, filled with friendship and good humor, we've also seen the struggles that come with the responsibility of being a Pokémon Trainer. From parting ways with old friends to losing loved ones, Pokémon has never shied away from tackling weighty subjects and tugging on viewers' heartstrings. Grab your tissues as we rank the 10 most heart-breaking Pokémon episodes.

10 Till We Compete Again

The final episode of Pokémon: XY was already an emotional one, as Ash had just lost another Championship. With their journey in Kalos at an end, Ash and his friends decide to part ways. While the goodbye was touching, it was Ash's parting from Serena that really struck a chord.

An old friend from Pokémon Summer Camp, the pair reunited years later, with Serena clearly having feelings for Ash. Viewers were on tenterhooks as they watched the budding relationship unfold, but it never fully developed. A tearful Serena bid Ash farewell at the airport, telling him she hoped they'd meet again when they're older, then shocked Ash by kissing him before running off to catch her flight.

9 A Poached Ego

Jessie and James have spent countless episodes hindering Ash and trying to steal Pokémon; however, in this adventure, the troublesome Team Rocket pair assume center stage as the heroes. Discovering that Pokémon poacher, Rico, has cages filled with Ekans and Koffing, Team Rocket decides to release the captive creatures.

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While Team Rocket's change of heart is touching, the episode takes a gut-wrenching turn as the duo set their beloved Arbok and Weezing free to rescue the captured Pokémon and lead them to safety. Having accompanied Team Rocket since the early seasons, it was moving to see Jessie and James give up their beloved Pokémon to save others.

8 Charizard's Burning Ambitions

As Ash's Charmander evolved, its attitude changed. As Charizard, the Pokémon seemed to lose all respect for Ash as a trainer and stopped listening to him.

Upon discovering Charicific Valley, filled with powerful Charizards, Ash was faced with a difficult choice: Leave or keep his old friend. Although Ash struggled to control Charizard, he still deeply cared for the creature. In the end, the young trainer had to do what was best for Charizard and left him with his fellow fire-type Pokémon. It was an emotional goodbye and would have ranked higher in the list had the pair not reunited for good in episode 773.

7 Go West Young Meowth

Jessie and James' impudent sidekick, Meowth often provides the show's comic relief. But in this episode, we get a glimpse into his painful past, revealing how he came to join Team Rocket.

Traveling to Hollywood as a young kitten, following promises of unlimited chicken and ice cream, he fell in love with a rich Meowth named Meowzie. Despite his best efforts, Meowzie rejected him for being poor. In an attempt to impress her, the young kitten learned to impersonate humans and joined Team Rocket in an effort to get rich but was rejected again for being weird. In the end, Meowth left with Jessie and James, who accepted him for who he really is.

6 Seeking Shelter From The Storm

Caught in a downpour, Ash, Serena, Clemont, and Bonnie dart into an old, abandoned mansion for shelter, only to discover the house is haunted by ghost-type Pokémon, Espurr. As the episode unfolds, we learn that Espurr has been patiently waiting for a friend to return: A woman named Lacy who lived in the house and would play with the ghost.

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Ash promises to find Lacy, but Lacy's granddaughter, Elise, appears and explains that Lacy has passed away. It's a heartbreaking end as Elise takes Espurr to the graveyard to place a flower on Lacy's grave; furthermore, Elise promises that Espurr can visit her anytime to play.

5 Gotta Catch Ya Later

It's never easy saying goodbye to friends, but when it was time for Ash to part ways with his longest-serving traveling companion, Misty, and briefly with Brock, it made for an emotional episode.

Ash and Misty's rocky relationship blossomed into a strong friendship over the course of 273 episodes. Despite becoming a firm fan favorite, the creators believed Misty had reached the end of her arc, so she returned to Cerulean Gym. It is a tearful goodbye as the original trio split and an emotional end of an era for many viewers.

4 The Stray Pokémon

The Pokémon franchise has sparked many discussions about animal cruelty, but despite criticisms, the series is conscious about tackling these issues.

Ash and friends discover a tiny Charmander sitting on a rock, having been told to wait there until his trainer comes back. The little lizard is stubborn in his belief that the trainer will return; in truth, the trainer thought Charmander was too weak and abandoned him. Nevertheless, Charmander waits out a Spearow attack and protects his tail flame from a raging storm, still believing his trainer would return. While he eventually joins Ash and is given unconditional love, the episode serves as a reminder that Pokémon are a big responsibility that need to be cared for, not a cute gift that can be quickly abandoned.

3 Bye Bye Butterfree

butterfree ash farewell

In 1998, hearts broke across America as Ash said goodbye to an old friend. The young trainer caught his first Pokémon in the show's third episode: A small Caterpie. With love and patience, Ash evolved Caterpie into a strong Butterfree.

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When the group encounters wild Butterfree on their way to Saffron City, Brock notes it's their season of love, and Ash decides to let Butterfree try to find a mate. The Pokémon is repeatedly rejected until he flaunts his strength during a Team Rocket attack. In a devastating twist, Butterfree would have to leave Ash behind. It was the first time Ash parted ways with a Pokémon and, more than twenty years later, remembering Ash's relationship with his little Caterpie still tugs on the heartstrings.

2 One Journey Ends, Another Begins...

Sun & Moon shocked viewers when it openly explored death and grief in a heart-wrenchingly tragic episode.

A stray Litten asks for Ash's help when his old friend Stoutland falls ill. Ash rushes the big-hearted Pokémon to the nearest Pokémon Center and Litten watches as Stoutland is treated. They return to their nest that night, where Litten dreams he is running after his friend, but can only watch as Stoutland slowly fades away. He wakes to find his companion has vanished. Overcome with grief, Litten refuses to eat or move until he is ready to start fresh with his newfound friends. It's a truly touching episode which deals with the mature subject matter in a heartfelt way.

1 Pikachu's Goodbye

While Pikachu may have taken a while to warm to Ash, from the moment they met, it was instantly clear they were made for each other. Their friendship is so notorious, it's hard to imagine one without the other.

That said, their relationship faced a real threat when they discovered a group of wild Pikachus. With Ash's Pikachu having so much fun with these new friends, Ash wondered whether it might be best to leave him behind. As a tearful Ash walks away from Pikachu, an emotional montage recapping their best moments together follows. Just as the audience is reduced to a weeping mess, Pikachu catches up with his trainer, choosing Ash over freedom in front of a crowd of cheering Pikachus. There's something in our eye...

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