The Yuuto Group was a business group of several Japanese software development companies led by Studio Panther/Panther Software Inc. president Satou Kenji. The members included the previously mentioned Panther Software Inc. (which held a controlling stake in the group), as well as CD Bros., D.O., and ZyX. Despite each company having different representative directors, Satou had full control over the member companies and had overall supervision of their games. In 2000, Panther Software Inc. changed its name to Interlex Inc. but continued to use the Panther Software name. Some time around 2004, a new company named Panther Software Inc. was established as a subsidiary of Interlex. In 2005, Interlex left the Yuuto Group, with CD Bros. taking over control of it, and Panther Software Inc. was spun off as an independent company, which later became part of Contents Traffic Co., Ltd.. In May 2009, the same time CD Bros., D.O., and ZyX became part of Contents Traffic Co., Ltd., Interlex changed its name to Interlex Core and its subsidiary Interlex Sales changed its name to Interlex.