Mouse Computer Japan, a build-to-order PC vendor, will ally with rival Arosystem to integrate component procurement and assembly operations. The partnership will yield them a combined market share of 7%. MCJ will take a 16.5% share in Arosystem, for about 400 million yen, making MCJ the second-largest shareholder in the firm. Cinex, an MCJ subsidiary, will handle component procurement for the two firms, while assembly will be concentrated at Arosystem's factory in Shimane Prefecture.