After the destruction of the bakufu, Emperor Godaigo inaugurated the Kenmu Restoration, where Nagatoshi became a samurai retainer to serve the emperor together with Masashige KUSUNOKI, a local ruling family in Kawachi Province, and served as officers at the Land Record Office, the warrior's office, the office of rewards, and the court of pleas; he was awarded a family crest which featured a sailboat.
幕府滅亡後に後醍醐天皇により開始された建武の新政において、河内国の豪族楠木正成らとともに天皇近侍の武士となり、記録所や武者所、恩賞方や雑訴決断所などの役人を務め、帆掛け船の家紋を与えられる。