According to Katsutoshi Eguchi, Japanese game developer Kenji Eno submitted the name and created the Dreamcast's spiral logo, but this claim has not been verified by Sega. The Dreamcast's start-up sound was composed by the Japanese musician Ryuichi Sakamoto. https://en.wikipedia.org/wiki/Dreamcast#:~:text=According%20to%20Katsutoshi%20Eguchi%2C%20Japanese%20game%20developer%20Kenji,was%20composed%20by%20the%20Japanese%20musician%20Ryuichi%20Sakamoto. might be worth looking into Kenji Eno