Stan Lee Media, the Internet-based animation production outfit founded by the co-creator of the “X-Men” and other Marvel Comics characters, has formed its first joint venture in Asia. Japanese animation house Venture Soft, which has a 3% stake in the Encino, Calif.-based company, will join with Stan Lee to form SLM Japan. Joint venture will produce, distrib, license and market Japanese and Korean versions of Stan Lee Webisodes, including a budding Backstreet Boys project and “7th Portal,” a Web series distribbed by Netcaster Shockwave.com being developed as a pic by producer Mark Canton. Financial terms of the agreement weren’t revealed, but officials noted that an initial public offering in Japan is planned. Deal marks Stan Lee Media’s second international pact, following an earlier agreement with Fox Kids Latin America to do online projects and related merchandising.