島巡り磯鍋競争！七包丁人大石老師登場

Master Oishi, one of the Seven Knives and instructor of the Setouchi Young Chefs, receives an order from Aji Shogun to defeat Yoichi. Due to his advanced age, Oishi tries to refuse, but his student Yuta unilaterally lures Ajio and Yoichi. When Yoichi heads to the Setouchi Islands, he is met with an island-hopping seaweed hotpot competition with the Setouchi Young Chefs.

七包丁の1人で瀬戸内少年料理団を指導する大石老師に、味将軍から打倒陽一の指令書が届く。大石は高齢ゆえに断ろうとするが、教え子のユウタが独断で味皇と陽一をおびき寄せる。そして陽一は瀬戸内へ向かうが…。