What's that Korean song?

I remember seeing a song from the MBC Music Box or something and so I
searched it up on Youtube.
The official Music Video:
In the beginning it's like drawings of a submarine. Basically
underwater ocean life. I think. And then there's a white room and
there's the band and then a girl who's singing. She has short hair.

And the song sounded a little techno-y.

PLEASE HELP. i'm desperate for this song.