Naoki Hisaya is a Japanese screenwriter who has worked for Tactics, Key, and Siesta. Born as Hayashi Naoki, he gained popularity as the main writer for the visual novel Kanon while working under Key. He also created additional works such as Moon., One Kagayaku Kisetsu e, and Moon Childe. Hisaya was originally a concept writer for Sola and has worked in a doujin circle named Cork Board. In 1997, he debuted as the main scenario writer for Tactics under Nexton, working on their second title Moon., followed by One Kagayaku Kisetsu e in 1998. After completing One, Hisaya and much of the staff left Tactics to work at Visual Arts where they formed Key. At Key, he worked on the planning and most of the scenario for Kanon, which was released in 1999. Following its completion, Naoki quit Key and participated in Comiket and C Revo between 1999 and 2002. In 2003, he became involved with the doujin circle "Black box" where he wrote their first doujin visual novel Limit Off. He also wrote the lyrics for its theme song. However, the project was frozen in August 2003 and has never been restarted again. In 2004, Naoki started working for Siesta as a sub-writer for their first title Moon Childe, which was released in December 2005. He then quit Siesta to work on Sola with illustrator Nanao Naru as the main concept writer. When Sola was adapted into an anime in 2007, Naoki wrote five out of fifteen episodes of its screenplay. He is also the author of the Sola manga series, illustrated by Chako Abeno.