Shiraishi is one of the 24 Abashiri convicts who had the map leading to the Ainu treasure tattooed onto their skins by Noppera-Bou. He is known as the Escape King, due to being a escape artist who has broken out of many high security prisons.
Shiraishi is carefree and goofy, and prefers to sneak his way out of trouble. Because he lacks strength, he prefers to flee danger but is confident in his ability to escape any bond. He tends to keep his calm when in danger as a result and given time, can psychologically dominate his guards and manipulate them.
(Source: Golden Kamuy Wiki)