Anata mo Watashi mo Doubutsu Dakara: Furin no Mori

This is a peaceful forest where herbivores live. Blessed with a husband and children, Momoyo, a flying squirrel, lives a seemingly happy life, but deep inside she feels an indescribable sense of suffocation. With a certain encounter as a catalyst, her destiny slowly begins to change...

(Source: Kurage Bunch, translated)

Note: Includes one extra chapter.