Far away in a land to the north of the north, there towered a great mountain, all year round covered in snow.
From its peak, billowing clouds of smoke, as if a giant were breathing out, poured forth from a pillar of fire, that reached into heaven in the darkness, and could be seen even from the distant sea.
Much like Taro the Dragon Boy the book divides into two halves. In the first adventure, while Kamu is saving his mother, he also learns of his missing father. Gamurii had thrown him into the northern sea, where he had turned into a white whale (no, I don't know either). Kamu sets off to find him and in doing so discovers that he must defeat the killer whale that is attacking the animals of the bay.
The similarities to Taro the Dragon Boy go beyond the larger structure. Both are made up of episodes that individually resemble traditional folk tales. Both have a young boy as hero, with a similar character in each, thoughtless, brave, assertive, good natured. Tellings of traditional Japanese stories of strong child heroes sometimes go in the same direction. It seems to me that in English children's stories such characters are rare, at least as anything like an identification figure. In Stevenson's Kidnapped for instance, the serious David Balfour is the figure with which the reader identifies, not the reckless Alan Breck; and in Arthur Ransome's books, Nancy Blackett is a strong character, but almost always seen from outside, while we are shown more of the inner life of more sensitive or responsible characters.