I was searching informations about "Hidekazu Yukawa", the SEGA's Marketing Director during Dreamcast era, and I saw that he did a song "Dreamcast" to promote the console. And he made a CD a for this ! So I managed to find one and I received it today.
The CD includes 3 songs : "Dreamcast" (see the clip here : https://www.youtube.com/watch?v=044_Aucg5OQ&t=169s ), the instrumental version of "Dreamcast", and a song where he tell the specs of the console xD
It's funny how the Japan's Dreamcast Marketing was, oh and here's also some photos of the disc :