I gotta agree that the movie was a bit mundane. Its plot was fairly basic, which is your typical story about accepting people's quirks and eccentricities, not saying that BDSM is weird in a negative way. Nonetheless, given that sex talk and BDSM are still seen as taboo and unconventional in a lot of communities, including South Korea, it is refreshing to see this premise from them, which is why I decided to give the film a 3/5 star review.
Although the actors acted well, I still experienced a lot of second-hand embarrassment when the male lead started barking, but then again, maybe some people are into that, IDRK. I'm just glad that topics like BDSM and sex are getting shed light on.
I would say that if the movie discussed the issues (being criticized and shamed for one's sexual preferences, getting consent, feeling safe, testing the waters for being a Sub or Dom and/or Sadist or Masochist, etc.,) more thoroughly, it would've been better.
To reiterate, although the movie was still lacking and "basic," I am hoping that it will be a stepping stone for future S. Korean movies and series that talk about taboo and controversial topics.