A Japanese salaryman shot dead on the eve of a long-awaited promotion is reincarnated by a god as Luciel, a fifteen-year-old with healing magic in a world where healers are universally despised. Determined to survive and build strength this time around, Luciel signs up with the adventurers' guild, only to discover that the training regimen includes daily doses of a foul-smelling concoction called Substance X that every other recruit refuses to touch.