A Japanese "Shiny Treasure ex" booster box is a premium set containing 10 packs, with each pack holding 10 cards, and it focuses on shiny Pokémon cards. The set includes over 170 shiny cards, featuring many Paldean starters and other popular Pokémon with shiny artwork. It is the final Japanese expansion for 2023 and includes both new cards and reprints, with high pull rates for rare cards like shiny and special art variants. 
Key features of the Shiny Treasure ex booster box
Set name: Shiny Treasure ex (SV4a)
Language: Japanese
Contents: 10 packs per box, with 10 random cards per pack
Theme: Features shiny versions of Pokémon, including Paldean starters and other Pokémon like Pikachu, Tinkaton, Ceruledge, and Charizard
Card types: Includes a wide variety of cards, such as shiny cards, shiny Tera Pokémon ex, special art rares, and gold cards
Card count: The set features over 170 shiny Pokémon cards
Release: It was the final Japanese expansion for 2023, released on December 1, 2023