The song might be part of a soundtrack for an anime or visual novel (like Himawari -The Sunflower- or a similar property). Use Japanese characters in your search: 向日葵は夜に咲く 新しいバージョン .
Go to OTOTOY (English interface available). Type the song title into the search bar. download himawari wa yoru ni saku new
For now, patience and legality win. By purchasing the download, you support the artists who created this beautiful juxtaposition of the sunflower and the night. Do not click shady “Download Now” buttons on pop-up websites. Do invest a few dollars into OTOTOY or Mora. The "new" version of Himawari wa Yoru ni Saku deserves to be heard in lossless quality—with the piano notes clear, the vocals crisp, and the emotional weight fully intact. The song might be part of a soundtrack