Isshun de Chiryou shiteita no ni Yakudatazu to Tsuihousareta Tensai Chiyushi, Yami Healer to shite Tanoshiku Ikiru

Born into poverty in the slums, Zenos has few opportunities, so he teaches himself healing after a chance encounter with a healer. When Aston invites him to join an adventuring group, Zenos is delighted, but the others treat him badly and eventually brand him useless, expelling him despite his efforts to improve. With nowhere else to turn, Zenos opens an illicit clinic and becomes a healer in the shadows. His skill quickly draws the attention of the city’s underworld, and his standing among society’s outcasts grows. But news of his reputation reaches the wrong people.