[Video] {MV} Dōshite Kimi wo Suki ni Natte Shimattandarō? (どうして君を好きになってしまったんだろう？

The literal english translation is Why did I fall in love in you? because the lyrics goes something like he found this person who he's sure is the one he is destined to spend the rest of life with, to love, be happy and all that jazz but that person is already happy, in love and (in the MV) marrying someone else :( and the persona says that it's okay that he's going to be miserable forever if only it would assure that the person he loves is happy forever :( :(