Cage of Cradle was a mobile phone comic that came out in 2006. Hiroyuki Owaku wrote the story, and Masahiro Ito did the illustrations. It was only released in Japan and focuses on Lisa Garland before the events that take place in the first Silent Hill game.
Some fan-translated panels from Cage of Cradle (click through flash file):
Trailer for Cage of Cradle, from the Japanese release of the first movie on DVD: