This paper examines and outlines the future exploration of AI companions, focusing on three main areas. Firstly, it defines AI companions as sophisticated AI entities designed for supporting and enhancing human experiences in daily activities, such as learning, working, and others. They encompass emotional, social, and practical aspects of daily life while fostering interactions and relationships with humans. Secondly, the paper provides a historical review of AI companions for learning (i.e., AI learning companions), offering an overview of their conceptualization, development, and utilization in educational contexts and insights into their potential future trajectory. Lastly, a research agenda is presented, which includes AI learning companions—outlining key questions, challenges, and goals for integrating AI companions into learning environments—and the pursuit of Global ‘Harwell’ (a portmanteau of ‘harmony’ and ‘wellbeing’). This suggests that, in addition to transforming education, AI companions can contribute to individual wellbeing as well as broader humanitarian objectives. Beyond contributing to economic growth and efficiency, it is fundamentally important to address the most pressing global challenges or human crises of our time, foster understanding and cooperation among researchers and practitioners in different fields, and hence pave the way toward a future world marked by Global Harwell. To further advocate and demonstrate the pivotal role of AI companions in achieving these genuine objectives, we propose the General Artificial Companion Hypothesis. All these endeavors, however, begin with AI companions for learning. As Mandela said, “Education is the most powerful weapon which you can use to change the world.”