A multipurpose robot conducting domestic tasks should be indispensable for social needs, and this type of robot requires sophisticated technologies. A humanoid robot is not really practical at present for actual home or hospital use, considering its reliability and cost. To develop a practical multipurpose robot, we previously proposed the robot-environment compromise system (RECS) concept, which involves technology to modify a robot’s environment to increase robot performance. This concept aims to share the technical difficulties between the robot and the environment so that robot tasks are possible and facilitated. The present paper reports the development of an indoor mobile robot system based on the RECS concept that has a wheel mechanism to traverse steps. We propose a navigation system based on image recognition of landmarks on the ceiling and evaluated its effectiveness in experiments. We also propose a positioning system using a docking mechanism. We demonstrate our proposal’s feasibility using domestic tasks of setting a meal on a table and clearing away the dishes. We also developed a human interface system based on speech synthesis and recognition.