Following news from two weeks ago that acclaimed Japanese studio Madhouse is produce an anime adaptation of the cult-hit series Supernatural, artwork has surfaced that just may be preliminary character designs for Sam and Dean Winchester.

AnimeNews reports that the sketches, which closely resemble the art in the background of Supernatural animated homepage, were discovered on the LiveJournal account of Andreas Ri, who has since restricted access to his blog. It's unknown what, if any, connection Ri has to Madhouse or to series character designer Takahiro Yoshimatsu.

Supernatural The Animation is set to debut in January in Japan as a 22-episode direct-to-DVD series that covers the first two seasons of the live-action show. The anime will remake some episodes while also introducing original stories centering on secondary characters and events from the childhoods of the Winchester brothers.

According to the Supernatural Wiki, actors Yuya Uchida and Hiroki Touchi, who dub the roles of Sam and Dean for the Japanese broadcast of the live-action series, will lend their voices to the anime.

Supernatural, which begins its sixth season this fall on The CW, stars Jared Padalecki and Jensen Ackles as Sam and Dean Winchester, brothers who hunt demons and other paranormal creatures. The fifth season, which ended on May 13, concluded a long-running story arc centering on the fight to stop Lucifer and save the world from the Apocalypse.