[ShiShiLeo]

The original OP for Hibiki was a pure instrumental track. I love that song too, but I was responding to the video dreamcastegirl posted which is the Shonen Yo song. Which is the ending theme, which I also love.

From episode 34 - 47 the opening song was changed to "To the Original You"

During the Heisei celebratory year of Zi-O, Shonen Yo was used as Hibiki's contribution to the Heisei musical remixes and themes, suggesting that Shonen Yo is considered by Toei the modern musical representation of Hibiki. Essentially, it was retconned to be Hibiki's OP.