Kouboku no Keibu

A helpful text message went out to people whose lives were in danger, guiding some of them to safety. This guidance system called itself the "Police Inspector." Later, a few people whose lives had been saved by the "police inspector" received another text, asking for help. This is how a group of three disparate people, high-schooler Natsumi, Shogo, and the gangster Teru, found themselves together, taking cues from a mysterious texter as they tracked down a criminal. But who or what is this mysterious texter, and can they really trust it?

(Source: MangaHelpers)