Share 'Who sings this song and what is the song called??????????'

If you can guess who AND what the song is called..I'll give you a cookie. ^^ jk, but if you do get it right I'll be surprise HINT: The song is in a Japanese movie! (And NO. Ikuta toma did not sing the song. I just felt like putting his picture up heh) Kono sora wa tatta hitotsu da to Itsu kara ka omotte ita noni Miageta kokoro no muki de Chigau no wa naze darou Itoshisa ni setsunai hikage ga…