Well, all the ones I’m watching currently have a strong second and even 3rd male lead syndrome. What I want in my dramas : no dark and gloomy SFL like “Cinderella and 4 Knights”  or “Cheese in the Trap” and no evil characters at all in it, just a light, fluffy, sunny and happy FL with an intense love triangle or reverse harem who has eyes for her alone. MLS are all pretty boys, rich and cold and eye candy in the drama and a happy ending please.

Just curious why you want a drama where you’ll get SLS? Isn’t that painful to watch, the FL choosing the ML over the SML that you root for? The reason I refuse to watch who are you: school 2015 is because i know i will get SLS and that’s too much for me to handle lol. Anyways try out that drama , it might break your heart for the second male lead...

 Vera :

Just curious why you want a drama where you’ll get SLS? Isn’t that painful to watch, the FL choosing the ML over the SML that you root for? The reason I refuse to watch who are you: school 2015 is because i know i will get SLS and that’s too much for me to handle lol. Anyways try out that drama , it might break your heart for the second male lead...

Because I wanna cry for the SML.

I don´t know how the Female Lead in Cinderella and the Four Knights is dark and gloomy for you, but here are my suggestions:

  • She Was Pretty
  • Accidentally in love
  • Radio Romance
  • Top Star Yoo Baek
  • EXO Next Door
  • Monkey and Dog Romance (A bit different from your request. Actually the Female Lead ends up with the Second Lead and most of the people shipped her with the Male Lead including me)
  • Failing in Love
  • Skate into Love

I really tried to only put light hearted dramas in the list and no dark stuff.

I actually never had a Second Lead Syndrome exept for Cheese in the Trap. So I don´t know how you feel about the Second Leads in my recommendations. But they are all Second Leads I felt bad for.

Most of them fit the bill, because there is a prominent love triangle, but in most I either didn't mind who FL ends up with or never had a SLS, This is my opinion only, I can be quite weird, unlike most I've never had SLS with Cheese in the Trap for example :-) Some of them have mild "evil" characters, but they are more annoying rather than anything and sometimes even help the love triangle with their presence. 

Cunning Single Lady

Go Back Couple - Had a MAJOR SLS, hated ML

Fated To Love You - ML is in love with somebody else at first, but she mistreats him and he falls for the FL before the drama is halfway. This drama has some angst as well. 

My Secret Romance

The Greatest Love 

Love Alarm

Discovery of Romance - got confused who is the ML and who is the SML in this. Also there is another girl who is in love with one of the MLs, he sees her as sort of a sister, but she does cause misunderstandings.

I second School 2015 for an enormous SLS , but this drama has some darkness in it 

High School King of Savvy  I don't remember much from this drama, but it definitely had a very prominent love triangle. I think many had a SLS. 

Go Ho's Starry Night - reverse harem, a fluffy short drama

Flower Boy Ramen Shop

To the Beautiful You has lots of handsome boys around (FL pretends to be a boy to go to an all-boys school) and it gave me INTENSE second lead syndrome! 

 Meg:
Go Back Couple - Had a MAJOR SLS, hated ML

+1 Go Back Couple - I don't remember hating the ML but I did ship Jang Ki Yong with Jang Na Ra  instead :(

Strong Woman Do Bong Soon - I actually like both guys with the FL but I almost cried at the end for Gook Du