the description of the audiogame real sound no regret was found on MobyGames, and the following is the description.
Mizu Sakura is a Tokyo elementary student who is transferred to a new school. There, she falls in love with a boy named Hiroshi Nonoichi. The two decide to elope together, fearing that nobody will accept their relationship at such a young age. However, Mizu never shows up for the meeting; a while later Hiroshi learns that she has been transferred to another school.
Several years have passed. Mizu is looking for a job and Hiroshi attends college. It looks like both have moved on with their lives. But their past catches up with them when they learn about a mysterious disappearance in the subway system.
Real Sound: Kaze no Regret is an audio game: it has no graphics or other visuals of any kind. Gameplay-wise, it is identical to visual novels, with written text and images being replaced by sound. The player listens to the voice-acted story, which is occasionally interrupted by a chime, prompting the player to make a decision and branch the plot.
hopefully you guys can update the description