30 Shunen Kinen Bon (高河ゆん漫画家30周年記念本 30 ――までだと思っていた道は、まだ先に続いている(といいな)) is an artbook celebrating Kouga Yun’s 30th career anniversary.
Includes some (not many 
) illustrations, interview with Nanase Okawa (CLAMP) and the original manga DARK COLOR. It was published by Ichijinsha in 2015.
Coloured pages: 
Download »5.14 MB download mirror: mediafire »
Interview: Download »44.39 MB download mirror: mediafire »
DARK COLOR: Download »19.68 MB download mirror: mediafire »