Yuichi Sakaki, a high school student, awakens one day with the ability to see people's true natures displayed above their heads, which he dubs 'Soul Reader' thanks to his sister's suggestion. Surrounded by individuals labeled as 'Zombie,' 'Vampire,' and 'Witch,' Yuichi's world takes a dangerous turn when he encounters Natsuki, a striking girl identified as a 'Serial Killer.' Luckily, Yuichi's sister has equipped him with the skills needed for such encounters. As the clash between the formidable assassin and the resilient younger brother looms, a thrilling battle unfolds.