 A sequel loosely based on the original One visual novel titled One2 : Eien no Yakusoku ( One2 ～ <unk> ～ , lit . One2 ~ The Eternal Promise ~ ) was produced by the visual novel studio BaseSon , another brand under Nexton . One2 was released first on April 26 , 2002 , and then again on April 25 , 2003 with added voice acting , scenario , CGs and music . One2 used the concept of the Eternal World established in One as a major motif as One had done . The Eternal World in One2 is better explained than in One , though the two versions of the world differ to a certain extent due to the scenario writers that worked on One not being credited on the production staff of One2 . 
