Zatch loses at a lottery to win a yellowtail fish and a man decides to take pity on Zatch and gives him his tickets to an onsen. At the onsen, Kiyo finds a note in his room revealing the location of a secret onsen and an all you can eat yellow tail buffet. Upon arriving at the location, Kiyo realizes that it's a trap and they attacked by a Mamodo named Baransha and her human partner Garza. Kiyo and Zatch are at a disadvantage since Baransha can attack from afar and become invisible. As the battle drags on, Kiyo uses ginkgo nuts' strong scent in order to track down the invisible Baransha. Kiyo and Zatch gain the upper hand with "Bao Zakeruga" but Garza and Baransha manage to escape by jumping into the river.
Zatch perde alla lotteria e un uomo vedendolo gli regala dei biglietti per andare alle terme. Alle terme Kiyo trova un biglietto con le indicazioni per arrivare a un buffet di pesce pinne gialle. Una volta arrivati i due si accorgono però che è una trappola.
Zatch pierde en un sorteo para ganar un pez cola amarilla y un hombre decide apiadarse de Zatch y le da sus entradas a un onsen . En el onsen, Kiyo encuentra una nota en su habitación que revela la ubicación de un onsen secreta y un todo lo que pueda comer buffet de cola amarilla.
山奥にある温泉旅館へとやってきた高嶺一家。温泉でくつろいだ清麿とガッシュが部屋に戻って来ると、秘湯・煮桃の湯と書かれた地図が置かれていた。そこには「ブリの食べ放題」という文字が！ すぐさま旅館を飛び出し山道を進む清麿たちを、遥か遠くから見下ろす二つの影。全てが周到に仕組まれた罠だったのだ。
