Manga, a Japanese comic, conveys contextual information about underlying stories based on the expression of a mixture of textual and pictorial elements. Two experiments were designed to assess whether individuals' eye movements when reading manga were consistent, independent of the specific materials, and stable over time. Experiment 1 examined the consistency of eye-movement parameters when participants read two distinct manga works and a narrative text and demonstrated that the parameters were consistent among the different reading materials. Experiment 2 provided evidence of the stability of parameters over time (i.e., an average interval of approximately 3 months). In summary, eye-movement parameters observed during manga reading were reliable stability indices over time and consistency among diverse materials. These findings imply that gaze behavior during manga reading could be an effective methodology for investigating individual differences in various aspects of cognitive processes, such as face perception and story comprehension.