One: Kagayaku Kisetsu e(One ～輝く季節へ～, lit. One ~To the Radiant Season~) is a Japanese adult visual novel, developed by Tactics, a brand of the joint company Nexton, and released on May 26, 1998 playable on the PC for Windows 95. Much of the staff that created the game later became the founding members of the visual novel company Key. The game was later ported to the PlayStation, and re-released as a full-voice version for the PC. A sequel loosely based on the original One visual novel entitled One2: Eien no Yakusoku was produced by BaseSon, another brand under Nexton, and was first released in April 2002.