ThestoryrevolvesaroundrenownedorchestraconductorThibaut.Whenhe’sdiagnosedwithLeukaemia,hesetsoutinsearchofacompatibledonorforabonemarrowtransplant.Hesubsequentlydiscoversthathe’sadoptedandthathehasanolderbrotherintheNorth.Thelatterisanofficeworker,buthealsoplaystromboneinalocalbrassbandwhichissoontobedismantled.Againstthebackdropoftheclosureoftheonlyfactoryinthearea,theirmeetingmarksthebeginningofafraternal,socialandmusicaladventurebbb