Kabaneri of the Iron Fortress

During the Industrial Revolution, a mysterious virus begins to spread, turning people into undead zombie-like creatures known as "kabane," who can only be killed by destroying their metal-coated hearts or by decapitation. Only heavily-fortified civilizations have managed to survive, such as the island of Hinomoto, which the residents surrounded with a massive wall to protect themselves, only accessible via armored trains. When kabane manages to hijack a train, a young engineer named Ikoma seizes his opportunity to test out a weapon he developed to pierce kabane hearts more easily. His weapon is successful, but Ikoma ends up bitten by a kabane in the process. However, his body manages to resist the virus, transforming him into something half-human, half-kabane – a "kabaneri." Alongside Mumei, another kabaneri, Ikoma and the remaining Hinomoto survivors set off in search of shelter elsewhere.