Un-Go character designers pako and Yun Kouga released an art book, UN-GO pako & Yun Kouga Design Works. They tag-teamed on the cover image:
UN-GO pako & Yun Kouga Design Works is primarily a collection of pako and Yun Kouga's designs―including some never-before-seen rough drafts―with their own comments, but also features a three person discussion adding in director Seiji Mizushima.
The book has a total of 79 pages and went on sale today for 1890 yen (a little over US $24). Fans who buy it at Animate stores receive a bonus illustration card while supplies last.