Background: Emotional design of multimedia lessons involves adding features that are intended to increase learner enjoyment and promote learning--such as adding narrative, anthropomorphizing non-human elements, and using warm colours. Objective: The present study extends this work to examine the potential of Japanese animation (anime) for improving science learning. Method: Specifically, 134 English-speaking students learned about cells in the human body by viewing the popular anime, "Cells at Work," either in Japanese with English subtitles or dubbed in English with no subtitles (anime groups), or by viewing a slideshow containing the same information (slideshow group). The anime conditions were vibrant story-driven lessons that depicted human-looking cells working to fight off invaders in a human body that looked like a city. The slideshow used very similar wording as the anime groups, and displayed the cells without anthropomorphism or a storyline. Results and Conclusion: The anime groups did not differ significantly from each other on any dependent measures and were therefore combined. The anime groups scored significantly higher than the slideshow group on retention (d = 0.35) and transfer (d = 0.48) tests. The anime groups also had significantly higher ratings of motivation (d = 0.60) and enjoyment (d = 1.13), whereas, the slideshow group had significantly higher ratings of distraction (d = 0.59). These results support the cognitive-affective theory of learning with media (CATLM) and demonstrate that anime may be an effective learning medium. Takeaways: Anime should be considered as a medium for science learning, especially when students might not otherwise be motivated to learn.