At first glance these two dramas aren't exactly similar but having watched both, there is a similar tone and vibe these shows give off. Though Sweet Combat is about boxing and martial arts and My Mr Mermaid is about swimming, both of these dramas are set during the college years with super cute main couples and a great group of friends though the friend group in My Mr Mermaid feels a bit closer. Sweet Combat also does have a bit more drama cliches (rich female lead with a disapproving grandfather) but overall if you like one, you'll probably like the other.