This entry contains spoilers for the Pokémon anime series.
Currently a work in progress.

Overview
Ash’s Kalos League Controversy refers to fandom reaction to a recent episode of the Pokémon anime series in which protagonist Ash Ketchum (or Satoshi in the original Japanese version) reached the finals of a significant tournament and failed to win.
Background
The event was notable in spite of having occured many times previously in the series because of several breaks in the usual formula. This time around, Ash reached the final of the tournament, which had not occured prior to the “XY&Z” arc of the series. He had a more typically “powerful” team featuring popular Pokémon from the recent games, and a member of his team, Greninja, gained a special form. Additionally, many other previous series traditions had been broken this time, and the next games in the video game franchise on which the series is loosely based, Sun and Moon, will not feature a typical Pokémon league. This led many fans to speculate that Ash would finally achieve his goal of winning the Pokémon league before the series moves on to follow the next set of games.
The series built towards the league tournament’s climax which would be resolved in the 131st episode (of the XY series only). The Japanese episode title for this episode was revealed ahead of its airing as “Kalos League Victory! Satoshi’s Ultimate Match!!” which fueled speculation yet further due to use of the word “victory” and the allusion to the fact that thus far, this is Ash’s greatest progress in the league tournament. Ash was set up to meet new character Alain, popular in his own right for being a different kind of character to the more typically “shonen hero” style of character in Ash.
Notable Developments
The episode aired on the Japanese network TV Tokyo on August 18, 2016. Bulbapedia summarised the events of the episode on their website, referring to the episode as “XY131” in accordance with their reference system, noting first and foremost:[1]
The Full Battle between Ash and Alain ends in Alain’s victory, making him the winner of the Lumiose Conference and Pokémon Champion.
The episode received negative reactions across Pokémon-related fan sites, including r/Pokemon,[2] where one user decryed the writing:
Ash is probably the only main character that will never win because of motherfucking plot armor
The comment received around 600 upvotes within 10 hours.
Discussion on popular Pokémon fansite Serebii.net featured a thread querying the reaction of Japanese fans compared with Western fans. Repliers agreed that reaction was negative on both sides of the world.[3]
Promotional videos for the episode on YouTube garnered a high ratio of “dislikes” on the Japanese web. One video managed to gain over 18,000 disliked compared to a measly 400 likes.[4]
Reactions on Twitter were mixed, and saw much discussion under the hashtag #KalosLeagueFinals.[5] 4chan’s dedicated Pokémon board, /vp/, also reacted strongly with a mix of negativity but also the usual trolling and shitposting.

Some /vp/ reactions to the episode as seen on August 18 2016.
Search Interest
Search interest for “ash kalos league win” shows a spike over mid-2016 running up to the airing of XY131.
External References
[2]r/Pokemon – Outcome of Ash vs Alain
[3]Serebii.net – The reaction to the latest Pokemon episode in Japan?
[4]YouTube – PV for XY131
[5]Twitter – #KalosLeagueFinals