Mochi Mayhem

The player is invited to participate in a student field trip to the land of Kitakami. Accompanied by Ms. Briar, a teacher guide from the sister school Blueberry Academy, the player travels to Kitakami and meets Carmine and her younger brother Kieran, two Blueberry Academy students native to Kitakami. The player is paired with Kieran and tasked with visiting three signs telling the story of "the Loyal Three".

Many years ago, the ogre-like Pokémon Ogerpon, who was wearing the Teal Mask, attacked Kitakami, but three Pokémon named Okidogi, Munkidori, and Fezandipiti sacrificed themselves to defeat it. Ogerpon was never seen again, and the villagers buried the three Pokémon in a shrine, named them "the Loyal Three", and have since held an annual festival to celebrate them. During the festival, Carmine and the player briefly encounter Ogerpon, who drops the Teal Mask before fleeing. Carmine stops the player from telling Kieran what happened, as he idolizes Ogerpon and she fears his feelings would be hurt if he knew he missed a chance to meet her.

The Hidden Treasure of Area Zero was announced during a Pokémon Presents on 27 February 2023. Combined, both parts of the DLC introduce over 230 returning Pokémon that did not appear in the base game (including all prior generations' first partner Pokémon) alongside new Pokémon. The Teal Mask introduces Dipplin, a new evolution for Applin, the Poltchageist line, which convergently resembles the Sinistea line, and the Legendary Pokémon Okidogi, Munkidori, Fezandipiti, and Ogerpon. The Indigo Disk introduces Hydrapple, the evolution of Dipplin, Archaludon, the evolution of Duraludon, four new Paradox Pokémon, Gouging Fire and Raging Bolt for Scarlet and Iron Crown and Iron Boulder for Violet (which resemble Entei, Raikou, Cobalion and Terrakion, respectively), and the Legendary Pokémon Terapagos. The epilogue introduces the Mythical Pokémon Pecharunt.

In The Teal Mask, which is based on the legend of Momotarō, the player embarks on a school trip organized by Naranja/Uva Academy's sister school, Blueberry Academy, to the land of Kitakami, which would also coincide with a festival in the village, whilst uncovering the truth behind a local legend. In The Indigo Disk, the player studies at Blueberry Academy as an exchange student, eventually travelling back to Area Zero, where they previously thwarted the corrupted AI professor's plans. In Mochi Mayhem, which serves to conclude the DLC (and Scarlet and Violet as a whole), the player's friends from Paldea join them on a trip to Kitakami, where things take an unexpected turn. The epilogue can be unlocked by acquiring a Mythical Pecha Berry via a Mystery Gift, along with completing both parts of the DLC as well as completing the Academy Ace Tournament in the base games at least once. The player must then investigate a Pecha Berry-like decoration (in fact, the dormant Pecharunt) in the shop in Mossui Town once these steps are completed to start the epilogue.

The Teal Mask received a score of 65/100 on the Metacritic reviewing aggregator, indicating mixed or average reviews. Fellow review aggregator OpenCritic assessed that the game received fair approval, being recommended by 39% of critics. Reviewers generally felt that while The Teal Mask enhanced the main game's strengths, the Teal Mask also exacerbated the main game's weaknesses: IGN's Rebekah Valentine cut to the chase on the game's volatility, such as "...the overall ugliness and performance issues did detract from locations that looked like they were probably quite beautiful in their concept art, just not their final execution..." In addition, Kotaku's Kenneth Shepard says The Teal Mask "embodies the best and worst parts of the original game", through "The story is where The Teal Mask shines in spite of the technical troubles, so perhaps fittingly, this DLC embodies both the best and worst parts of Scarlet and Violet."

Outside of the worse performance issues (such as frame rates and graphics), the Teal Mask received generally good reception on the story and music. However, one aspect that was not present from the base game is that The Teal Mask lacked the freedom to explore the region, since there was only one story to focus on, resulting in linearity. In particular, Sports Illustrated's Ryan Woodrow shared that "There are plenty of little caves and nooks in the world of Kitakami, but they aren't as rewarding as the ones you can find in the main game." Despite this, The Verge's Charles Pulliam-Moore claims that "...one of the most unexpectedly pleasant things about The Teal Mask is how strongly it establishes Kitakami as its own distinct space that exists within the larger world." Further, the Digital Trends' Giovanni Colantonio commented that "[the] central story doubles down on Scarlet and Violet's storytelling strengths by telling an endearing tale that's custom-built for young players."