Maru leaves home because his family loves him too much, and that detail alone tells you everything about what this show is doing. A cat realizing he's been replaced, getting hurt by the very people who made him soft and safe, then choosing to walk into the world alone, that's not cute slice-of-life, that's a story about how comfort can become invisible abandonment. The show refuses to look away from how a loved thing can feel worthless the moment something newer arrives.
Maru is a portly tabby living the comfortable life in a Matsuyama household, pampered by his owner Anna and fed so generously that his waistline expands with each passing day. The cat spends lazy afternoons pressed against the window, watching the world drift by while contentment settles into his bones. Everything changes when a sleek new kitten named Cerisier arrives at the home, suddenly drawing all the family's attention and affection. Maru's jealousy festers as he watches his beloved humans fawn over the newcomer, and a confrontation between the two cats leaves him wounded by harsh words he never expected to hear. Stung and desperate to reclaim his place, Maru heeds the counsel of a street-smart feline and abandons the only home he knows to venture into the world beyond his window. What begins as an act of stubborn pride becomes an unexpected journey of rediscovery, forcing a well-fed house cat to confront what he's really looking for and who he actually is without the comfort he's always known.