Get ready for the most generic song description ever... Sorry!

Apart from the friend that introduced me to dramas a while ago, I have never met anyone in real life who knew dramas. Today though, I heard a person humming a song that sounded extremely familiar! Somehow, I'm sure it comes from a drama. I'm very curious about what it was!

But the only lyrics I recall are the ones I heard her say, which are something like "I love you ba-aby", then ummm.... la la la laaa lala.... (haha I was trying to get the rhythm in there but not too sure that worked...) and then finally something that rhymes with "baby" at the end. It's a romantic song of course, but it's not slow or soft. An upbeat pop song. Oh and it's a guy singing it, I think.

For some reason I feel like it comes from a very famous drama... Pretty sure it's either korean or japanese too.

Does anyone have an idea? 

Thanks for your help!
You have 41 completed drama's in your list. Check the ost of every romance drama in those 41. I know, it's a lot of work. But when I'm having this problem I am capable of going through every drama ost on youtube. :')
I've been doing that, still can't find it :^/ I'm thinking it may be a drama I haven't watched, but somehow know the song of haha
I've gotta say, It really sounds you're describing 'Can't Take My Eyes Off You'. I'm pretty sure I've heard that in drama and/or K-variety... And covers in music shows.