Obviously, both have Lee Min Ki in it. Although BTIMFL is more preppy and happy, they both are in the slice of life genre, showing the events in the mundane lives of normal people. They both discuss certain topics that are quite relatable to the public, like insecurities, societal pressures, relationships and their fragility, workplace toxicity, and just the overall hardships of being a broke young adult with nothing to your name.

Both of these BL stories involve childhood 'friends' who always try to one-up each other in everything they do, since they were young. However, their relationships further develop into something more because of a "I must protect you" dynamic.

These two are just weirdly similar. Most obvious similarity is of course the actress who plays the FL, Yoo In Na.

These two also feature a love triangle with the FL, the ex-husband, and the current flame (husband, in the case of TSWLM). In both, reason for the divorce of the FL and ML was somehow a misunderstanding/communication error, and the second male lead is really a good person as well, and shows that he really does care about the FL.

There is also some degree of mystery to both, since there is a murder that they need to solve and a criminal that they need to pursue. The FL in both is a strong woman who handles her own business/department and gets things done, although how she deals with her love life is a bit questionable.