Sylvia June Day is a Japanese American writer, widely recognized for her notable contributions to literature. Writing under the pseudonyms S.J. Day and Livia Dare, she has captivated audiences worldwide.

She is a number one bestselling author in 29 countries, with an impressive record on the New York Times, USA Today, Sunday Times, Globe and Mail, and Der Spiegel bestsellers lists. Her works have been translated into 41 languages, selling over 20 million copies in print.

Notable works include the bestselling Crossfire series, with titles such as "Reflected in You" and "Entwined with You." Her book "Aftershock" reached number one on various bestseller lists in its first week of release.