Yumeko is shown to be a very upbeat and charismatic character who consistently attracts the affection or interest of people around her, usually making a big scene. Not only is she able to befriend those who previously disliked her, she is able to catch the attention of the entire student body. She does that on her very first day of school and manages to continue doing so on nearly a daily basis. Every time she notices an opponent cheating in games, her button gets switched to a bloodthirsty side of her, usually seen when her eyes turn red, and she frightens her opponents. But... things start to get darker when Jabami is connected to the mysterious murders of several students from her own school and other people as well. Jabami uses her fortune that she earns in these gambling games to pay and order the murder of other people, but she herself admits to never having killed anyone.