Flower, Sun and Rain is an adventure/mistery game originally released on japanese Playstation2 consoles in May 2001.
The game has been translated and re-released on Nintendo DS consoles worldwide through 2008 and 2009; However, the port is substantially inferior in both the graphic and music departments, which in my opinion damages the overall atmosphere of the game; The port is now out of print, though second hand copies are quite abundant.
Suda has hinted at a possible remake/remaster coming later down the line. Meanwhile, you can either play the NDS version, or play the PS2 version while following along this script as it matches the english translation.