The use of robots in education has the potential to engage students in learning activities and aims to form lasting relationships with them. To encourage sustainable, long-term human-robot interactions, a promising approach is to cultivate a pet-like, interdependent relationship. However, the potential of such relationships in education remains unclear, and the limited availability of robots in classrooms necessitates flexible and scalable designs. To address these challenges, this study leverages digital twin technology to facilitate ubiquitous engagement with pet robots, thereby prolonging interdependent relationships through a SeamlessPet robot learning approach. Here, students engaged with both virtual and physical pet robots, enabling realistic and continuous interactions akin to communicating directly with a physical robot. This integration ensured consistent availability and authentic interactions, enhancing educational outcomes demonstrated in situational presentations. An experiment with 70 university students in a Japanese Hospitality Management Program in Taiwan demonstrated that this approach resulted in better learning achievements and fostered a positive learning experience. The pet-like features embedded within the digital twin robots played a vital role in fostering prolonged learning participation, empowering students to take ownership of their learning, stay motivated, and feel supported at any time and from anywhere in the learning process. Educators and curriculum developers are encouraged to consider this approach, particularly in courses with a final project presentation that uses a robot to demonstrate study results.