Small mystery box is an item released with the Boat to the Arc. It is one of the possible rewards for helping with the activity in Port Sarim. It is rewarded by Seasinger Umi when your personal progress reaches 100% and after the event based on thresholds of both community and personal progress at 20%, 40%, 60%, 80% and 100%. Thus, a maximum amount of 6 small mystery boxes can be received.
Players will always receive a prismatic lamp and star, along with random items from the box's drop table.