I know it's a very large time area, but I'm greatly interested in a few books to read about the region.

Specifically, I'm interested in:

• Three Kingdoms of Korea, up until Goryeo
• Pre-warring States/Qin China
• Chinese relations with Korea & Japan during these times
• Japan up through the Asuka especially, but up until the Kamakura era in general

Something in depth enough that can teach me more than a general history textbook of the region/wikipedia, but not too detailed as to warrant a tens of thousands of pages.

Very specific, I suppose. Sorry if it's inappropriate.