English name: Irisu Syndrome!

Free, very hard, and [b]creepy[/b] puzzle videogame starring [[Irisu Kyouko]].

There is a story following [[age hatori|Agetha]], [[edogawa takeru|Edogawa]], and [[uujishima satoshi (irisu)|Uuji]], a group of university students.

[spoiler]Based on how you play, you will either get a [[Bad End|Bad Ending]], which leads to death of the 3 university students.  Or a [[Good End|Good Ending]] where it is just a scary surprise party.  Or a perfect ending (in Metsu) where Irisu becomes sane, Uuji starts down the path to sanity as well, and all 4 of them -- Irisu, [[age hatori|Agetha]], [[edogawa takeru|Edogawa]], and [[uujishima satoshi (irisu)|Uuji]] are all friends.[/spoiler]

In February 2010 an expansion called いりす症候群！滅 (Irisu syndrome! Metsu -- aka Irisu Syndrome!  DESTRUCTION) was released, with hints of a 2nd expansion in the works.  Metsu explains the entire story.

This is a free game.You can download it here:

http://www.vector.co.jp/soft/win95/game/se463417.html

And here is the artist's website for the game:

http://members.jcom.home.ne.jp/wtetsu/index.html
いりす症候群!