Lina, who is isolated because she is the daughter of a Count with a reputation for being black, was despairing about her future because her fiance was devoted to a female servant of the academy. But after eating the confectionery given to her on her birthday, the world changed. She acquired a strange skill called “Block.” Insults directed at her are shut out (muted)! Certain people can’t get close to her anymore! Lina, who was happy to have a peaceful life, saw disturbing dreams and couldn’t easily cancel her engagement. That’s when the duke who gave her the confectionery and his knight cooperated with her.