song name sun and sunflower: by flower. (taiyou to himawari)
one is a techno-ish version, one is the original acoustic. Either or works fine. sorry, but I apparently can't post links...
so the first one named exactly as "FLOWER - Taiyou to Himawari [Video Lyric]"
the second is
"Nightcore - Taiyou To Himawari [lyrics]"