Kinou, Kimi ga Shinda.

In a post-apocalyptic world where humanity has mostly vanished, Hazukuro, a humble tailor, is left to mourn the death of Godou—the man he has secretly loved since their school days. As Godou draws his last breath in front of him, Hazukuro's heart shatters. But just as despair sets in, a devilish-looking stranger appears and offers Hazukuro a strange "magic sewing machine" with a chilling promise: to bring Godou back, albeit in an artificial, humanoid form. Using the sewing machine, Hazukuro painstakingly stitches together a new version of Godou—identical in appearance to the real one. To Hazukuro’s amazement, the newly sewn Godou comes to life, moving and speaking as if he were real. But there’s something missing—this Godou lacks the human soul that once made him whole. Despite the physical likeness, Hazukuro knows that the essence of the person he loves is absent. The devilish man, still lurking in the background, reveals that Godou’s soul is out there, somewhere in the world, waiting to be "sewn" back into the body. With little more than a needle, thread, and the mysterious sewing machine, Hazukuro sets out on a perilous journey across the ravaged landscape, seeking the fragments of Godou’s soul. What awaits Hazukuro and Godou at the end of this journey? (Source: Gentosha Comics, translated)