both are having Best as one of the main characters, however, CO is less appreciated than KKB!
for CO it's a co-worker's relationship while for KKB! it's about sharing a house with 3 strangers
(in my opinion, KKB!'s story is less messy tho)
The main leads in these series checked-in the resort to heal their broken heart. Somehow, their rooms are next to each other allowing them to get to know more about the other. They have a romantic encounter there at the resort.
Two strangers meet at a get-away-resort. Fate has them as next door neighbor which allows them to get to know each other and fast becoming friends then turn into lovers.