Fire force 4.

A new action fantasy set in a steampunk Tokyo from the creator of the smash hit Soul Eater!

FIRE BUGS
Shinra has discovered that someone is using a bug to turn people into Infernals. He’s narrowed the suspects down to two, and now he must figure out which one is the real culprit. Can he find out who is friend and who is foe without first getting caught himself?