The storyline really is messy. Starting from Lee Young Ae become a homie gamer addicted for 5 years due to her guilt for accusing her husband of murdering his student which caused him to take his own life.
I thought the main case supposedly finding out who the real killer is while solving other cases, but it's not, more likely chasing a psychopathic serial killer as well as psychopathic politician Mama.

Idk which one is the messiest, it's even wasted more than 1 eps to get Koo to handle the cases. It was still acceptable for me until ep 4, but it just keep going downhill.

At first, the drama directed the viewers as if the serial killer is also the student's murderer, so I thought it's still on track. But then, after ep 3 or 4, the focus is changed, the student murder case was never brought to attention again until the very last eps... the serial killer thought her that Santa was with the student, so there's no way Koo's husband killed her.... but still, if Santa is a witness.... who is the killer, is it a murder, an accident or suicide? No one knows.

I'm annoyed how Mrs. Sook and Yi Kyung's psychopathic characters really use the same "JOKER" wannabe vibe. Not to mention, how ridiculous in the last ep, when Mrs. Sook can cooly move and face all reporters after getting heavily injured by a BOM.... casually moving with burn injuries in half of her face and hand... seriously!!!

I'm also annoyed with the inconsistency.

There's no explanation on why Yi Kyung gets very obsessed with Koo. Some scenes show Yi Kyung desperately wanting to have some friends, but when Wook gets shoots in the last scene, she just leaves him there bleeding out..... He is her only friend.

Koo was known as a great investigator, but she has no willingness to know who is Santa... like... why??? Seriously? What make it even more "funny", when Yi Kyung asked "why don't you do a background check on him? Don't you want to know why Santa is helping you? You're not even paying him." And her replied of "He just does it because he is Santa, a man doing good for no reason" sending me to the deepest part of the earth. Is it me being overthinking for believing that is no ordinary human being doing something that far, without hidden agenda... we're talking about risking his life for free, for God shake. He is human! Not a real Santa Clause!
As a police academy graduate, she's not even capable enough to have a "proper" fight with Yi Kyung.

Santa gets close to her and helps her due to his guilt for not testifying for Mrs. Koo's husband's innocence.... but why does he have to wait for 5 years just to do it? And a wall full of Mrs. Koo's pictures out of guilt... sing like a psycho while observing/adding those pictures... this is a sick obsession
There's also no explanation on why Santa refuses to talk to Koo and the team. Only refuse to talk to them...., remember, he even sings when he is alone. As if he is scared that if they hear his voice, a big secret will be revealed.

Last but not least... I hate how she keeps coming back to alcohol every time she failed.