Hi everyone, 
I'm looking for a drama where one of the leads (preferably the male lead) is in love/ has a crush on someone else (preferably unrequited), but then they come to fall in love with the other lead.
Ex- My GF is a gumiho
Full House
Bring it On Ghost
Another Miss Oh
Delightful girl Choon Hyang
Thank-you in advance!
Hey Ananya! I think you'd enjoy the following:

Cinderella and 4 knights
Jealousy Incarnate (there are a lot of crushes lol)
She was pretty


@-executedtoperfection- I was actually thing about picking up JI, but seeing the posters, it looks like there's a strong love triangle. And my poor fragile heart always ends up with SLS, so I kinda avoid it XD
Warm and Cozy
Kill me heal me
Fated to love you
Goong
Nagareboshi
Smiling Pasta

Smile, You
Cain and Abel (2009)
Fated to Love You both versions
Goodbye Mr. Black
Innocent Man (2012)
Kill me heal me
One Sunny Day (2014) short
Rooftop Prince
Thank You (2007)
--that's all in my list
Please love the useless me
Secret (korean drama) This one definitely ;)
Who Are You: School 2015
Weightlifting Fairy Kim Bok Joo
A Girl & Three Sweethearts (happens to the second male lead)
That Winter, The Wind Blows
Cain and Abel (japanese drama, happens to Yuu)
Falling for Innocence (happens to female lead, kind of to the male lead too)
Mask (kind of)
Innocent Man

It's on the older end of things but Heartstrings was this way.  And rather than being super frustrating I thought his devotion to the first woman showed how devoted he was going to be to the female lead.  
Beautiful Mind (female lead yes & sorta the male lead)
Good Doctor (again the female lead)
Heart to Heart (female lead yes & sorta the male lead)
One More Happy Ending (female lead)
well i can only think of heavenly forest( **** spoiler: if u wanna happy ending then dont go for it)
and also senpai to kanojo