Wo de Laopo Shi Zhi Mao

A skilled black rat named Xiang falls in love with a cat girl named Xiao Ji. Xiao Ji is considered a disgrace and traitor to the cat clan and is banished, while Xiang is hunted down. According to the cat clan's rules, if Xiao Ji and Xiang's marriage doesn't gain the approval of Xiao Ji's parents before Christmas Eve, Xiao Ji will never be able to return to them. Thus, Xiang and Xiao Ji embark on a journey to seek acceptance…

(Source: Bangumi, translated)