Mana visits Sakaiminato, where her aunt and uncle live. She was looking forward to the festival, but loses her enthusiasm after finding out that it might not be held this year. In order to cheer Mana up, Uncle Shōji decides to go fishing so he can feed her the most fresh and liveliest fish he can catch. However, he doesn't return. Mana and the town's fishermen set out by boat to find the missing men, to soon be attacked by Funa-Yūrei. These Funa-Yūrei were recognized to be the missing fisherman, including Uncle Shōji. Mana is the only one to survive the attack and washes up on shore. Kitarō arrives and heads to sea by boat to investigate. There, he encounters the Funa-Yūrei and the yōkai Umizatō that was supposed to have been sealed away!
Mana retourne au village natal de ses parents pour l'été, mais de mystérieuses disparitions en pleine mer viennent ternir ses vacances...
まなは叔父、叔母が住む境港を訪れていた。祭が開催されないと知り残念がるまなを元気づけるために、叔父の庄司はまなに活きのいい魚を獲ろうと漁へ出るが、そのまま戻ってはこなかった。町の漁師たちと船で捜索に出たまなは、沖で船幽霊たちに襲われる。なんとその船幽霊たちは行方不明となっていた庄司たちだった。船は沈みまなだけが浜辺に打ち上げられ生き延びた。助けに来た鬼太郎は船で霧のたち込める海へと向かう。そこで船幽霊たちとともに封印されていたはずの妖怪・海座頭と遭遇する!