[lars512]

Kanji contain repeated elements ("radicals"), which form something of a graphical alphabet. Learning a new character's form is not too difficult then, you can identify that it's radicals A, B and C, in this kind of arrangement. Basically, it's neatly pre-chunked for memorisation.

The pronunciation of kanji is more difficult than their visual layout, and arguably where most of the burden is in Japanese. A single kanji can have pronunciations it's picked up from several periods in history. In practice, it just means that it might have a handful of different pronunciations in different contexts. Learning all these contexts takes time.