Name of Song when that the guy whistles before it plays

When she goes to the building that is white the guy is whistling a song then she hums it a little, after the song plays does anyone know the name of this song, I think its a love song, Anyone know the name of the artist and the name of the song eitehr in chinese or in english?

I have uploaded the sound clip here : http://www.megaupload.com/?d=AA2GEGU6