I'm a little conflicted with this manga on a cultural level. It seems to support letting cats roam free outdoors.
Cats are a plague on the environment and lead to millions of birds dying while also causing considerable pollution as their excrement enters waterways. Once a number of feral cats are present, they can breed two possibly even three times per year. Cat populations quickly reach the maximum sustainable by local resources, but continue to breed leading to countless avoidable kitten deaths. Occasionally an older feral cat will die and the young cats might split his territory.
Please remember to spay and neuter your animals, and never let roam free outdoors. Humans created them, they do not belong in any ecosystem.