The setting is a different world. The male protagonist is a veteran and the female protagonist is a teacher. They are involved in a huge conspiracy involving human existence due to investigating the mysterious disappearance of their mother twenty years ago. The protagonist's ally is a lawyer, and the villain is the heroine's alien mother. The story revolves around the investigation of the heroine's disappearance. In the process, he discovers that there is a greater secret hidden behind the heroine's disappearance.
Motto: True love can overcome all difficulties