This drama had the potential to be an entertaining short story but, instead, several things made watching it frustrating and infuriating.

1) The female lead character has potential but her naivety, recklessness and obsession with her first love make her story very frustrating to follow.
For her teenage love of vacation, she doesn't hesitate to work in a creepy hostess club or to jump into the water in winter to recover a damn strap.
Her lack of survival instincts and intelligence are frustrating to watch. Especially for a boy she only knew during vacations when she was a teenager. Seeing a young woman sicken with sadness, throwing herself headlong into danger and unable to move forward in life due to an unhealthy obsession with her first love is hard to watch when the moral is...that she's right.
She also has no judgment and believes the first comer when it was easy to see the person was threatening her out of jealousy. Also, she should at least give her friend the benefit of the doubt before condemning him for the words of a stranger.

2) The romance between the leads is not believable and infuriating. They remain stuck at their 17th youngself, unable to move on. The FL is depressed (and depressing) while the ML sinks into a dark world while cherishing their memories of times that were (understandably) better. Instead of seeing two young adults find each other again, cherish their memories, help each other in adversity and get to know each other or, on the contrary, realize the past is over and part as good friends we have two people who act like teenager while they're no longer children.
The FL has deeper, serious and interesting relationships with her best friend and her new friend/suitor the photographer with whom she shares many things in common (hurtful first love, passion for art...).

I don't recommend it, it will only frustrate the audience because we see everyone, except the romance between the leads, be a more interesting story.