Anna Akechi is a 14-year-old second-year middle school student living in Makoto Mirai Town. On her birthday, guided by the fairy Pochitan and a pendant she finds in her room, she time-slips from 2027 to Makoto Mirai City in 1999. There, she meets Mikuru Kobayashi, a 14-year-old girl who dreams of becoming a detective. Suddenly, a robbery incident occurs, as someone has something precious to them stolen. Figuring that the "Phantom Thieves" may be responsible, and driven by the feeling that "I can't ignore someone in trouble", Anna and Mikuru transform into Cure Answer and Cure Mystique. Together, they become the , running the Cure It Detective Agency while solving mysteries and searching for a way for Anna to return to her original time.