Boku wa Sonzai Shiteinakatta

As a long time anime fan and music connoisseur (record collection dates back over 100 years), Boku wa Sonzai Shiteinakatta truly is a song worth listening to. From its soothing sounds that let you feel the emotions it inspires to its excellent harmony.
The computer visuals from this original authorized release weren't that bad considering that it was just an internet release at a time several years before the actual anime was broadcast and the English subtitles allows many other people to appreciate the song and it's message.
This was the Debut single with Sony Music Japan that can be viewed legally on the 22/7 official ... YouTube channel, which is surprisingly still active with new uploads in 2023.
Even if you don't watch idol anime at least give the song a listen!