Both are mystery-thriller dramas and they both have an 'investigation' to find the 'culprit' behind the act. 'Rumor' is somewhat darker than 'Find me if you can' (which has lighter moments). Both dramas are based on real-life topics: 'Find me if you can' is based on stalking and also showcases bullying. kidnapping, manipulation. While, 'Rumors' is based on rumors (obv) and their effect on people, being a victim of workplace bullying and judgement.
Both have a starring female character. In 'Find me if you can', the 3 male characters like the main character, while in 'Boyfri3nds', the 3 male characters are her 3 boyfriends. While 'Find me if you can' is mostly focused on a darker topic- stalking, it also has a surrounding romance and comedic plot, while 'Boyfri3nds' is mostly focused on romance and comedy.
(SPOILER: There is a slightly darker plot-twist).
(SPOILER: There is a slightly darker plot-twist).