Yearbook Mystery Box

The Yearbook Mystery Box is an ex limited-time consumable released on March 13th, 2019 as part of A Classless Reunion 2019 Event. It is the biggest mystery box to date, as it contains almost all of the content that was previously released for the game.

Contents
This particular mystery box possesses a new feature that lets you "Refresh" to cycle through the full contents of the box, displaying only five items at a time. When you purchase the box your prize would then be selected from only the displayed items.

The contents of the box are separated by the slot that contains them, similar to how the vault operates. Slot 1 items will never appear in Slot 2 no matter how many times you refresh.

Trivia

 * During the March 14th update, the Yearbook Mystery Box's store icon had its end date removed, making it permanent, as there's no end date in the files.