Most of the books I read don't have translations I could read instead. But 龍の子太郎 (Tatsu no kotarou), the 1960 children's novel by MATSUTANI Miyoko (松谷みよ子 1926-), seems to have translations in both English and German. I've taken the post title from the English translation (which I haven't read). It's another book aimed at younger readers, a story told in folktale style and based on elements of various Japanese folktales. Probably most people starting on Japanese at some point read some version of the more famous Japanese children's folktales like Momotarou and Issunboushi. A full length novel on the same sort of material is likely to be more of a challenge. Still, it's a fairly easy book to read, though the dialogue might occasionally demand some experience (or guessing).
Tarou is a common boy's name or part of a name in folktales. Tatsu no ko means dragon's child and was added to Tarou's name by the village children, mocking the birthmarks on his body, which looked like a dragon's scales. Tarou is an orphan, cared for by his grandmother, who tirelessly works in the fields to provide for him, while he goes playing in the hills with the wild animals. One day, a drum-playing red demon kidnaps Tarou's friend Aya, a flute-playing girl. Tarou sets off to get her back. And this is the start of a series of adventures that will lead him to find his mother, who, it turns out, is not dead, but transformed into a dragon.
Putting together folktale type stories to make a larger story sounds easy enough. But it works very well here. Like The Hobbit, the episodic story turns out to add up to much more than the various parts. And it's quite subtly done. As you read, you enjoy the lively folktale style and scenes; but when you get to the end, you see where the story was heading, although there was no didactic over-emphasis along the way.
The story has been dramatised several times. There's a 1979 cartoon, which is available in Germany at least (as Taro Der Drachenjunge) and seems to be well regarded. I haven't seen it yet, as it currently costs 25 Euros. (Germany is like Japan in this respect: they reckon the fans will pay what they're asked.)