You can find the full lyrics and audio for "Akai Usagi," the opening theme from the 2008 Blade of the Immortal anime, on SoundCloud or by watching the original opening video on YouTube . For sheet music, you can explore fan-made transcriptions at Ichigo's Sheet Music or use transcription tools like Piano2Notes . Blade Of The Immortal OP - Akai Usagi (Lyrics) - SoundCloud