Here's the artbook of Daisuke Igarashi (五十嵐大介), a manga artist from Japan. The artbook features works from 1993, when he started his professional career, up to 2012.
This is a two paperback book set that comes with a slipcase. The 128-page Book I features marine themed illustrations, and the 208-page Book II has the manga artworks. His illustration style focuses on line art and the colours seem to be watercolours.
In Book I, you'll see some of the coloured illustrations from his manga series Children of the Sea (海獣の子供) and other marine themed art. and other works which have elements of fantasy and nature. His surrealism and spiritual theme has sometimes been compared with Hayao Miyazaki.
Book II has the manga work and features selected panels, drafts and commentary. It's pretty cool to see the panel progression, and the different styles he uses, which are the line art and watercolour.
Visit Amazon to check out more reviews.
If you buy the links, I get a little commission that helps me get more books to feature.
Here's the Amazon Japan buying guide for your reference.