The Japanese "Mask of Change" booster box is the 6th set in the Scarlet & Violet era, released on April 26, 2024, and is the Japanese counterpart to the English "Twilight Masquerade" set. It features the Pokémon Ogerpon, with four new Tera ex cards, and cards for trainers Carmine and Kieran. A standard box contains 30 booster packs, with each pack holding 5 cards. 
Key features
Main focus: The set centers on the Pokémon Ogerpon and its four masked forms: Teal Mask, Hearthflame, Wellspring, and Cornerstone.
Artwork: The set includes cards with special art, some depicting Ogerpon's four masks and others showing characters like Carmine and Kieran with unique illustrations.
Card types: Look for cards such as the four Tera ex cards of Ogerpon, numerous Special Art Rares (SARs), Art Rares (ARs), and ACE SPEC cards.
Box contents: A single booster box contains 30 booster packs, and each pack contains 5 cards.
Set details:
Release Date: April 26, 2024
Set Number: SV6
English Twin: Twilight Masquerade
What to expect: Pulls from the set can include valuable cards, including the four Ogerpon Tera ex forms, and special art versions of trainers like Carmine and Kieran.