Manga Kill My Love

From hscans:Certain lovers are selected anonymously, only to find a strange symbol etched to their necks. Once those who are selected get too close to each other, or within the “Danger Zone”, one of them will die an explosive death. Suspicion, scheming, and murder… Once star crossed lovers, now enemies, willing to kill each other without hesitation… Ning Yuan, a young emotionless man, is suddenly thrust into this cruel game of death. How will he protect his “Soulmate”?