I watched Happiness coz I believe both main characters, Park Hyun Shik and Han Hyo Joo..., I was wrong.

The drama premise is about a zombie-like virus, firstly spread by pills then infected people distributed by bite and scratch, but it has its own uniqueness. People who got infected are still able to get back to their human form, as long as they don't smell blood. Kinda like Sweet Home, but the virus is curable in the end. Apocalypse's setting is not my favorite but I still can watch it.

What frustrated me the most is the characters. In Sweet Home, all residents work together to face the situation. The older brother and his ballerina sister,  the priest, the firefighter, the gangster, etc... all characters are strong and have special contributions to the drama.  Antagonist residents exist but it still makes sense. And they're still willing to join other residents when cooperation is needed.
While this one has nothing but a compilation of useless evil and trashy characters. The one that useful are only both main characters whom the other characters trying to get rid of throughout the drama...., as if all of those characters have no common sense to UNDERSTAND, how much they need these cops in this critical situation

To make it clear, these disturbing behaviors happen throughout the drama, literally from the start till the end. The word "useless" I use refers to their contribution to the story. And these weird characters keep doing their disturbing behaviors, as is they forget that they are in a very critical situation.
Start from a very trashy useless YouTuber wannabe boy who is very rebellious and disregards his mother. He has no job but to play games and live streaming. He humiliates his mother, even mean enough to steal all of their food stock and leave their parents after his mother got infected.
The apartment-representative wanna-be woman, who wanted to get rid of the main characters for no clear reason and I can't even mention which one of her acts is the most disturbing.
A doctor who killed his wife, for the whole drama trying so hard to kill Hyunsik, .... the reason is by killing him, none will come to catch him....??? As if Hyunshik is the only cop who will chase him for his crime. I can't find the logic in which killing the police in charge is the best way to get away with your crime.
The doctor's mistress who only cares to chase for the doctor's money.
The cleaner couple who is very money-oriented.
The cleaner employee, Andrew, who mysteriously wears goggles and masks but then happens to be a serial killer.
A money-oriented lawyer with his useless protagonist wife.
A writer, the other useless protagonist with her useless brother who keeps pestering his sister to give away her apartment because he lost him and he needs a place for him and his family to stay.
Hyunsik's partner who can easily betray him for no reason, and gets easily forgiven.
A girl who has to stay at home coz of her sickness... but never shows her symptoms. She has no contribution but stays at home and be Han Hyo Joo's playing mate.
Seriously, if you delete one of those characters, it will have no impact at all.

To make it, even more, weirder, for the whole drama all characters keep believing and follow the doctor and the representative's words, even though the cop couple has already proven that they are not only can handle the situation, they also can communicate with authorities outside, which make them know what they should do. Such as how long the quarantine will last, how the food will be delivered, etc...
But, these residents, instead of believing the cops, they sided with the antagonist duo and conspired to kill the cops, even using Andrew's service to get rid of all the cops... as if living with Andrew, a murderer is way better than the cops. I can't accept the logic.
This antagonist duo is even able to convince the whole residents to kill resident 1501 for his food stock...  People can turn their survival animalistic if they are in extreme condition, but they're not even that starved yet!!

Until the last episode, those whole antagonists really did not pay enough for torturing me for 12 eps. The trashy YouTuber can come back to his parents with no consequences; the doctor and the representative are jailed, but unclear for how many years; the brother becomes a test subject for the vaccine; the cleaner, the lawyer, the mistress etc status also unclear

I kinda regret investing my time to watch this drama. All characters, besides the main character, are very frustrating and just contribute to my stress and anger level.