The Tree of Death: Yomotsuhegui Vol. 2 (manga)

Among us live the Undying, who feed the fruit of the Yomotsuhegui to those who seek eternal life, or even just a momentary rescue from death, and thus these immortals increase their numbers one by one… Can the Shinigami Ren and former police officer and current Undying Nawa save the world from a fate worse than death with their special gift—the power to grant mortality to those doomed to live forever?!