Kouboku No Keibu summary:

A text message would be sent out to people whose lives were in danger, guiding them to safety. This mysterious system called itself the "Police Inspector". One day, three youngsters—who had been saved by the Police Inspector in the past—receive another text. This time, it is the Police Inspector who needs help. Now, Natsumi, Shogo, and Teru work for the mysterious texter, who gives them clues as they track down a criminal. But who or what is this mysterious texter... and can they really trust it?