Shinryû (真竜), 1804-1856, was a gô (art name: 號) for Yoshihara (Yoshiwara) Nobuyuki (吉原信行), whose other gô included Ôhô (王峰) and Tôin (桃隠). His familiar name was Yosaburô (与三 郞). Shinryû was born in Bungô province in eastern Kyushu (southwestern Japan) and studied painting in Kyoto with Mihata Jôryû (worked c. 1830s-early 40s). Recognized as a highly skilled painter during his lifetime, Shinryû received the title of hôgen (lit., "eye of the law," 法眼, here indicating the second highest of three honorary ranks awarded to artisans and artists). He was also honored with an invitation to visit the imperial palace in Kyoto. Shinryû's specialty was bijinga (pictures of beautiful women: 美人画), as in the charming example shown here.
The beauty's lower lip is colored with sasabeni (bamboo red: 笹紅), a mixture of red (beni) and green from the bamboo (sasa) plant. The green applied over red on the lips imparts a shimmering effect. Beni was also used as rouge brushed on the cheeks and upper eyelids, seen here as a pale pink, but when used for the lips (called kuchi-beni, or mouth red: 口紅), it was more concentrated and applied with the middle finger (the process was called beni sashiyubi, or "finger-pointing red"). Japanese women partly hid their fleshier lower lips by first applying white powder called oshiroi (白粉) and then adding beni and sasa on top.
Shinryû's painting of a bijin (beautiful woman: 美人) is an example of abuna-e (dangerous pictures: 危絵) or pictures of a mildly suggestive nature. As she adjusts her yukata (thin, unlined robe: 浴衣), possibly soon after bathing, her breasts and left leg are exposed. The bijin's red susoyoke (thin, half-slip underskirt with ties: 裾除け) provides a shock of contrasting color with the blue and white yukata, and it is echoed by the red hairbow, which tends to attract the eye upwards along the length of her slim figure. Japanese of the period (and many today) would recognize the color red as an erotic code, further identifying this beauty en dishabille as an object of sexual desire for the male viewer.
References: Roberts, A Dictionary of Japanese Artists, p. 148