日暮里署管内でで起きた殺人事件の被害者の会社へ行った徳之助は東北駅弁大会で「会津福福弁当」を譲ってくれた女性・沙織（鳥居かほり）と出会う。沙織と同僚に犯人らしき人物の似顔絵を見てもらうと見覚えがある顔だとわかった。南会津の名物・シンゴロウを露店で売っていた男だと調査
Tokunosuke, who went to the company of the victim of the murder in the jurisdiction of the Nippori station, meets Saori, a woman who handed over the "Aizu Fukufuku Bento" at the Tohoku Ekiben Tournament. He found Saori and her colleague a familiar face when he saw a caricature of a person who seemed to be her criminal. Investigate that he is a man who sold Minamiaizu's specialty, Shingorou, at a stall.
