Both are BLs about the relationship between one of the leads who is human, and the other lead who is a cat(or dog)/human shapeshifter who begins living with the human.
While in Beside You only the cat turns human and is the love interest, in CMS both deceased cat and dog return reincarnated to their owner, the dog being the love interest.
Café setting, reluctant falling in love, easy flowing dynamics, humour, some heartbreak. These two shows feel very similar to me and I enjoyed the laidback tone of both.
