Sorairo Days was released in 2007 as the opening theme for the anime series Tengen Toppa Gurren Lagann, performed by Japanese singer Shoko Nakagawa. Its bright, optimistic sound matched the show's story of unlikely heroes rising to fight for humanity, and it quickly became one of the series' most recognisable musical signatures. Over the years, fans have kept it alive through anime music videos, tribute edits and short-form clips, where even a brief excerpt signals determination, teamwork and the excitement of starting something huge.