Some ratted this drama very badly. And I will not. First, because you need to discard the remake from 2016 that was really bad. First, because the respect between the original movie from 2014 and the series staring Fluke Teerapat and Fluke Natouch. Before talking about the series, you need to watch the original movie. The story about those two brothers (not blood related) who felt in love against an homophobic father and a society who fought against LGBT during that time (the story is between the 90s and early 2000s).
But, while the story is about homophobia and acceptance, this drama 5 years later show the changes over time. In 2015 the LGBTQI in the U.S can marry legally. So, while Golf "died" in 2013 and went to live with his Half-sister in the US, he saw the changes and when he came back in 2018, the wold had changed toward the LGBTQI community. So, this series make sense, and people who rated it so low didn't even try to understand it.
On top of that, if I remember correctly, this was from the real life of real people. (For example, the group Axis, from Gondola Entertainment is where the two characters came from). Look online for more info.