While many of Ash's former traveling partners made a come back in the anime's final series, May wasn't among them, and the reason is heartbreaking.

As the Pokémon anime with Ash began to move towards an ending, many of Ash's former companions in Pokémon made guest appearances. May and her brother Max, however, were not among them, with their appearance limited to a non-speaking cameo. It turns out that the reason for May's absence has some tragic real-world origins.

May was the first female character to switch into Ash's party, taking the spot that once belonged to Misty. She was also the first female anime character based on a protagonist from the games, something which would become a bit of a tradition with Ash's traveling companions, at least up to XY. May also began the exploration of Pokémon Contests, a new mechanic in the Ruby and Sapphire games which provided her with a much clearer goal than the one Misty had. It's clear, looking back, that May was an extremely influential character on the anime, so her absence in the final season of the show was noticeable. It wasn't because they didn't want to bring May back, though; it just wasn't an option.

May Was Absent From Pokémon Out of Respect for Her Actress

In the original Japanese version of the Pokémon anime, May (known there as Haruka) was voiced by an actress known as Kaori. Kaori voiced May throughout the Hoenn era of the anime, and into her appearances in Diamond and Pearl as well. However, in 2012, Kaori announced that she had received some medical news that would dramatically impact her career. Kaori was suffering from a disease known as spasmodic dysphonia, which impacted her ability to speak and sing. According to her announcement, she first began experiencing problems back in 2007, which would've been right around the time of May's last (speaking) appearance in the anime. Kaori retired from singing and voice acting in 2012 as a result of this diagnosis.

While it has never been stated (at least in English) that this is the reason for May's absence, it seems that the producers of the Pokémon anime were unwilling to recast May as a result of this turn of events, and instead opted to simply leave her out. Max, as her younger brother, couldn't easily show up without having to come up with an excuse for May to be missing, so he was benched as well. While May didn't appear outside of her silent cameo in Journeys, she was referenced on several occasions, in particular during the episode "Reuniting for the First Time!", which sees Serena guiding Chloe through the world of Pokémon Contests. At one point, Serena gets Chloe to try on an outfit once worn by the "Princess of Hoenn"--none other than May. While May would've been the ideal choice to guest star in this episode, they were at least able to pay some respect to Kaori and her performance as May.

The Pokémon anime's decision not to recast May in Japan was a bold one, but when a character has been portrayed by the same actress for as many episodes as May was, replacing them just doesn't come easily. Kaori expressed in her announcement that she hoped to get back on stage someday, and no doubt there are many Pokémon fans who would love to see that again, too.