Heartslabyul

Heartslabyul (ハーツラビュル寮, Hātsurabyuru Ryō) is the first dormitory, released on March 26, 2019. It has five members: Riddle Rosehearts, Ace Trappola, Deuce Spade, Trey Clover, and Cater Diamond. Heartslabyul was founded on the severity (厳格) of the Queen of Hearts, and is inspired by the world of Alice in Wonderland.

Trivia

 * Every member of the dormitory is shown to be wearing a red-stained white rose. This references the part of Alice in Wonderland where the Queen's gardeners plant white roses by mistake and attempt to paint them red so she doesn't notice. The Queen does and gleefully orders for them to be beheaded.
 * Based on Riddle (Heartsabyul's current dorm leader), students of this dorm are to never get low scores in test and are law-abiding residents, following the rules that was created by the Queen of Hearts.