AI and robotics have advanced rapidly. Within this context, AITubers - content broadcasters operated entirely by artificial intelligence - have emerged, introducing novel legal challenges and safety concerns. This paper examines the legal landscape surrounding AITubers within Japanese law, focusing primarily on civil liability. It begins by contrasting traditional VTubers, where a human operator is directly involved, with AITubers that lack an identifiable “person behind the avatar” (naka-no-hito). The discussion then explores the potential implications of granting AITubers legal personhood, including the viability of treating them as corporate entities or unincorporated associations, and how such recognition might affect the allocation of legal responsibilities. Furthermore, the paper analyzes scenarios in which AITubers may act as perpetrators of defamation or other harmful acts, as well as cases where they become targets of defamatory or malicious attacks. Special attention is given to the responsibilities of AITuber operators, including the necessity of implementing safeguards to prevent the generation of problematic content, and the role of commenters in influencing AI behavior. By evaluating theories such as Prof. Saito’s approach to avatar legal personality, the study argues that, despite emerging complexities, existing legal frameworks may still adequately address the challenges posed by AITubers.