If You Linger, You Will Become a Shadow.

On the first day of traveling through the ninja world, the system showed that he had less than 24 hours to live. But killing enemies can save your life. Shinichi decided to follow up behind Metkai and hit the target. Perfect. The only bug is: Shinichi kills too many enemies. He kept killing, and the village thought he was capable. As he continued to do his job, the enemy began to focus on him. Staring and staring, he became famous. Nowadays, there are rumors in the ninja world: There is a murderer in Konoha who never attacks directly, but everyone who meets him is dead. They don't know that Shinichi is just a coward who wants to live, but becomes a shadow as long as he lives.