Three years ago, Lucas met a unique girl named Camilla, who had just transferred to his school. Initially, Lucas was very cold to her, despite her attempts to be friendly. Camilla persistently chased after him, trying to engage, and they eventually discovered something they had in common. Over the next few months, they became close. However, one day, as Lucas was about to head home, he saw Camilla lying on the floor, stabbed holding her wounded area. From that moment on, he blamed himself.