Maru begins as a shelter cat adopted by Anna in Matsuyama City. Content initially, consistent feeding causes significant weight gain, confining Maru mostly to observing the garden from a window. This routine shatters when Cerisier arrives, receiving abundant family attention. Consumed by visible jealousy, Maru clashes with Cerisier, feeling rejected by the family. Following another cat's advice, Maru leaves the household to explore the world beyond the garden.

Subsequent experiences prompt Maru's self-reflection and transformation. After secretly witnessing Anna's musical performance, Maru becomes captivated by dance, expressing a deep desire to master it. This aspiration ignites a dedicated journey of training focused on self-improvement and physical change. Maru tackles personal limitations through practice and perseverance, symbolizing an evolution beyond initial jealousy and hurt. This narrative arc concludes Maru's story within the Ehime trilogy, marking a progression from domesticity to a purposeful pursuit of new experiences.