Sayuri Kurata
In episode 14, Sayuri reveals that had a littler brother, Kazuya. Sayuri was raised by her dad to always have good manners and when Kazuya was born, she adopted a tough love approach to raising him and treated him strictly so he will grow up to become strong. However, she really wanted to play with him and give him what he wanted and see him smile. Kazuya then suddenly became sick. When Kazuya’s condition worsened, Sayuri went out to buy water pistols and snacks for him and played together with him. According to Sayuri, this was the “first and last memory of playing together.” When Kazuya dies, Sayuri starts to refer to herself in the third person since she can only view herself objectively.