This may be some older news, but I’ve finally found some time to make a post about it. A while back, a side story for Kono Sora was announced. It is a side story for Kotori and will take place after you’ve dated Kotori for some time. The story stars the protagonist spending time alone with Kotori during the winter break. Some new features include: motion events movies, binaural recording, and 3D modeling of Kotori. Included with the game is a maxi single of her character song and a drama CD. The game is set to be released on May 30th, 2014 and will cost 5800JPY. A complete edition that will include the original game, Flight Diary, Snow Presents, and a bonus box will cost 13800JPY.
Source: Product Page