SMBRYMS (브림스) is the creator of under PRIN. She first published underPRIN in 2008. Her "Owner character" (drawing that represents her) has short hair, so many mistook her for a man. She lives in Cheongju City, Chungcheongbuk-do, which is why both UnderPRIN and Golden Change take place in Cheongju City. Many locations in both webtoons are based on actual places in her city, as she notes in her blog.
She often prioritizes work before her own health, which is why she suffered from insomnia and wrist pain while creating UnderPRIN. Readers always urge her to take better care of herself.
Not much has been released about her, but she does have a twitter, so if you can read Korean and find anything out, please contact us.