Aoishiro is an all-ages, yuri visual novel developed by Success.
It is considered somewhat of a sequel to Akaiito, also, a yuri visual novel by Success, and the two seem to share the same world.
The original release of the game was for Playstation 2 on May of 2008.

In November of 2009, the game was ported to PC.
Modifications included high-res, less-censored CG.
In addition, there were some extra CG and two extra side stories were added.
There is also a mode where you can design your own Aoishiro scenes using a proprietary scripting language.