Catgirls (also known as nekos (ネコ, cat in Japanese)) are a species of cat-human hybrids that live alongside humans in the Nekopara universe. Catgirls were once left homeless and living in the streets, but now they are domesticated by humans and aren't allowed to go anywhere by themselves without their masters unless they have bells. Catgirls are a humanoid species with some cat features (ears, tail, etc). They also have breeds akin to cats. In addition, they have mating seasons. Though they can't mate with humans, they can be romantic partners with humans in which they will be referred to as catpanions.
Chocola - The youngest (together with Vanilla) of the nekos and is Vanilla's biological twin. She has developed a close attachment to Kashou and couldn't bear to be separated from him. Her cat breed is unknown.
Vanilla - Chocola's biological twin and has a very close relationship with her. Vanilla rarely expresses her true emotions and has a kūdere-type and stoic personality. Her cat breed is unknown.
Azuki - Eldest and shortest of the Minazuki's nekos. She has a mischievous and energetic personality and oftenly picks fights with the others. She is a Munchkin Cat.
Maple - The second eldest of the nekos. She is well-informed about technology and enjoys visiting various shops and restaurants to try different foods and drinks. She is an American Curl.
Cinnamon - The third youngest of the nekos. She often interprets and expresses everything in a sexual manner, resulting her to be aroused. She has a very perverted personality. She is a Scottish Fold.
Coconut - The second youngest of the nekos. She possesses a very womanly body though she isn't confident about this and instead, yearns to be called cute. She has a cool personality according to the others. She also appears to have very low self-esteem, and tends to think about things such as suicide when she fails to do something or doesn't meet the standards of others. She is a Maine Coon.
Milk (also known as Food Stand Cat) - A catgirl who manages a takoyaki food stand situated in the park where Kashou, Chocola and Vanilla often visit at during their break hours. She has a similar personality with Chocola, being cheerful and friendly even to new acquaintances. Her cat breed is unknown.
According to a Q&A question in the Kickstarter for the Anime OVA, Catboys do exist.