Takayuki Aihara is a videogame music composer who has published under the pseudonym J99. His first contributions to game music were for arcade titles, including Ridge Racer 2, Galaxian^3, and Tekken. In 1996 he composed music with Shinji Hosoe and Ayako Saso for Street Fighter EX and Soul Edge. The three were later hired by Square to produce the soundtrack for Bushido Blade.
In 2000, Shinji Hosoe left Arika to found Super Sweep, and Takayuki Aihara joined the new game music production company. Their next project together was Driving Emotion Type S. Following that project, Aihara collaborated with Super Sweep composer Nobuyoshi Sano on the Drakengard original soundtrack. Since then, he has been involved in remixing tracks for Phantasy Star Online Premium Arrange, Rogue Galaxy Premium Arrange, and the Street Fighter Tribute Album.
He is now a freelance composer, from his Studio Carnival company and since 2009 has worked on the theme for Baldr Bullet Equilibrium, the rock-based score for Power Punch and the tribute album for NieR under the pseudonym NO‐NO₂which was published by Square Enix.