The 23rd installment of the long-running Precure series. 
 
Anna Akechi is a second-year junior high student living in Makoto Mirai Town. On her 14th birthday, she has a chance encounter with a fairy named Pochitan, and a magical pendant caused her to travel back in time from 2027 to 1999! In the Makoto Mirai Town 28 years in the past, Anna meets Mikuru Kobayashi, a girl her age who wants to become a great detective. 
 
Meanwhile, people in town are in trouble as their prized possessions are being stolen from under their noses - the cause being a group of Phantom Thieves. To stop them, Anna and Mikuru turn into Pretty Cures! Maybe if they solve these mysteries, Anna can find her way back to her own time? 
 
(Source: Official Website, translated)

Meitantei Precure!