This episode features Taro, a schoolboy known for his tall tales. His newest claim? That the special feeding regimen for his pet turtle will cause it to grow big enough for Taro to ride on and take him to a castle under the sea. After being removed from class he witnesses a bank robbery, but the school faculty doesn't believe him. Looking for his errant turtle he stumbles across the robbers, who kidnap him, until Taro's turtle grows enormous and scares them into surrendering to the police. Climbing bareback, Taro rides Gameron to the legendary castle under the sea, where Otohime, a princess, chides him for being a compulsive liar.
授業そっちのけでカメの飼育に夢中の太郎少年。夢は大きく育ったカメに竜宮城へ連れて行ってもらうことだ。ところがある日、強盗事件を起こしたギャングが、彼のカメを連れて逃げてしまう！
