The story is about a 15 y old girl name Snowdrop who is in highschool, and secretly a assistant. her parents moved away when she was 9 to go their "mission". One day, a kidnapper kidnapped a 6 year old girl while they were walking to their friends house. So the police department depends on Snowdrop to rescue the little girl and eliminate the kidnapper. Eventually they set a partner with her, It was a boy name Kaito. He speaks Japanese but he also secretly speaks English also he just loves to mess with Snowdrop, Will they able to survive and save the girl?