Kanashiki Debu Neko-chan  

The Sad and Fat Cat, かなしきデブ猫ちゃん

The anime revolves around a feline character named Maru who was rescued from an animal shelter in Matsuyama. Loved and well-cared for by his human family, Maru grew rounder and more obese with each passing day as he spent most of his time lounging near the window and observing the garden outside. However, when a new cat named Cerisier joined the household and began receiving all the attention, Maru became envious and upset. In an altercation with Cerisier, Maru was injured by the family's words towards him. Following advice from another feline companion, Maru decided to venture out into the world and explore his surroundings.