Koroshiya S no Yuragi

Known only by the codename "S," a ruthless and cold-blooded assassin has built his reputation on an unbroken record of eliminating every target he is assigned. His lethal precision has never wavered, making him one of the most feared figures in the criminal underworld. However, his flawless streak faces an unprecedented disruption when he accepts a new contract: assassinating Kirito Furukawa, the seventeen-year-old daughter of a powerful Yakuza boss. As S closes in on the young girl, something entirely unexpected shatters his hardened exterior. For the first time in his life, unfamiliar emotions begin to stir deep within his heart, completely dismantling his professional detachment. Unable to pull the trigger, the once-relentless killer makes a drastic choice that alters his fate forever. Rather than taking her life, he abandons his original mission and dedicates himself to protecting Kirito as her personal bodyguard, stepping into a dangerous new role where his former employers may now view them both as targets. This compelling tale of redemption and shifting loyalties earned critical recognition early in its run, receiving a nomination for the Tsugimanga 2020 Award in the Manga Category.