Hokusai, Utamaro, and Kuniyoshi are among the most well-known names sought by collectors of traditional Japanese art of the 17th to early 20th centuries. Woodblock prints of the ukiyo-e period are highly-prized for scenes such as a gentle snowfall around a temple.

The same artists depicted much more heated moments, specifically erotic scenes that make today's auction house interns blush, but were originally intended as part of intimate "pillow books" for couples.

Phaidon Press has compiled a new book with 350 full color images representing the best of these Shunga, or "spring images." Poem of the Pillow and Other Great Stories: Erotic Japanese Art by Utamaro, Hokusai, Kuniyoshi and other artists of the Floating World will be available in June.