Recently, a super-aging society has developed in many countries around the world. The research and development of PRs (personal robots) that improve the quality of human life is needed in order to accommodate the aging society. Elderly people will be able to spend their lives happily and effortlessly with the aid of useful and convenient PRs. However, excessive or premature use of PRs may cause health deterioration or contribute to the quick aging phenomenon. In this paper, a new prototype PR is proposed that can follow human beings with their baggage. Elderly people, therefore, will be able to go outside empty handed to shop, enjoy the fresh air, and visit friends. This PR will encourage people to walk outside and can eventually support an active lifestyle in its true sense. For actual use, PRs should have both a small footprint for coexistence in human society and high traveling performance for following the human wherever they go. Active posture control for the roll and pitch angles is applied to the PR to realize these requirements. The proposed structure and control approach using lateral acceleration as a control variable is verified by experiment using the new prototype robot.