This is a fan disc of Tsukihime containing one short visual novel story, two omake stories and other fan materials.

Akira Seo, an underclassman of Tsukihime's Akiha Tohno, becomes acquainted with someone calling themselves Shiki Tohno, and together they set out to solve the mystery of a recent series of murders.

[From [url=http://en.wikipedia.org/wiki/Tsukihime_Plus-Disc]Wikipedia[/url]]