Getchu: http://www.getchu.com/soft.phtml?id=11750 (Overall)
http://www.getchu.com/soft.phtml?id=19505 (Azrael)
Official: http://frontwing.jp/product/426/index.html

Not much I can say here since I haven't really played them. It's a collection of 3 visual novels under one unifying name of 426 I guess.

The games don't particularly look like the pure love type with sad girls in the snow, so anyone who wants those, considering yourself warned.

BONUS: For the etymology of the game that most people seem to like out of the collection... well, here it is.

http://en.wikipedia.org/wiki/Azrael