A Japanese visual novel video game developer that has developed a number of visual novels, including eroge. They also have been collaborating with developer Type-Moon to create the light novel series Fate/Zero. Their works usually have dark themes such as reanimation of the dead, rape and murder. They also have a branch of the company called Nitro+chiral, which focuses on Boys' Love visual novels. Writers aligned with the company, such as Gen Urobuchi, have also contributed to various manga, anime, novels, and television works.
