Hint 1 - Korean drama
Hint 2 - Action Drama
Hint 3 - About Underworld Drug Issues
Hint 1 - Korean drama
Hint 2 - Cold cutthroat investor
Hint 3 - His personality changes to goofy
Falling For Innocence! 
Hint 1 : Japanese Drama
Hint 2 : The main girl is cute but quite talkative
Hint 3 : She gave all the support to the guy she fell in love with
Itazura na Kiss - Love in Tokyo?
Nope~ Ok Here's another hint: The main guy started up a business with his partner, who then betrayed him later on.
Haha, I have no idea. Someone else is going to have to guess.
Rich Man, Poor Woman?
YES!!!!! Correct @Utaku! I guess it's your turn! ^^ 
Yaaay!!! Let's see...

Hint 1: Japanese drama
Hint 2: There are 4 male protagonists
Hint 3: An old friend of them appears as the 5th protagonist
I still can't figure it out. Can you give one more hint please?
No clue? Can you give us another hint?
no Idea ,, can we have  another hint 
Still no hint? Please give a hint!!!