Go! Anpanman: The Amazing Naganegiman and Yakisobapanman

Yakisobaman and Uncle Negi try to escort the young Pepper Trio and their important cargo to Vegetable Village in time for the carnival this evening but Baikinman and his gang are trying to steal the cargo. Luckily, Naganegiman keeps showing up to help fight them off, but how? Who could this mysterious masked swordsman be?