"Mobile21 Co., Ltd. (\u30E2\u30D0\u30A4\u30EB\u30CB\u30B8\u30E5\u30A6\u30A4\u30C1\u682A\u5F0F\u4F1A\u793E) was a Japanese video game developer that was a 50/50 joint venture between Nintendo and Konami established on October 7, 1999. Mobile21 primarily concentrated on next-generation Game Boy Advance development, with a particular interest in mobile phone linking features."@en .