add-on. Though Naka was not directly involved in the Sonic CD development, he exchanged design ideas with Ohshima. Following the release of Sonic & Knuckles in 1994, Yasuhara quit, citing differences with Naka. Naka returned to Japan, having been offered a role as a producer. He was placed in charge of Sega's Consumer Development Department 3, also known as CS3. Naka was reunited with Ohshima and brought with him Takashi Iizuka, who had also worked with Naka's team at STI. In the mid-1990s, Sonic Team started work on new intellectual property, leading to the creation of Nights into Dreams (1996) and Burning Rangers (1998) for the Sega Saturn. Naka stated that the release of Nights is when Sonic Team was truly formed as a brand. The Saturn did not achieve the commercial success of the Genesis, so Sega focused its efforts on a new console, the Dreamcast, which debuted in Japan in 1998. The Dreamcast was seen as opportunity for Sonic Team to revisit the Sonic series, which had stalled in recent years. Sonic Team was originally creating a fully 3D Sonic game for the Saturn, but development moved to the Dreamcast to align with Sega's plans. Takashi Iizuka led the project; Iizuka had long wanted to create a Sonic role-playing video game and felt the Dreamcast was powerful enough to achieve his vision. The game became Sonic Adventure, launched in 1998, which became the bestselling Dreamcast game. Around this time, CS3 was renamed to Sega Research and Development Department 8 (R&D #8). While sometimes referred to as AM8 or "Sega-AM8", based on the R&D structure being titled the Sega Amusement Machine Research and Development (AM) teams, Sonic Team focused solely on home console games. Until 2000, media referred to Sonic Team's designation as both R&D #8 and AM8. 1999–2003: Dreamcast and Sega restructuring In 1999, shortly after the release of Sonic Adventure, twelve Sonic Team members relocated to San Francisco to establish Sonic Team USA, while others remained in Japan. Shortly afterward, a number of key employees—including Ohshima—left Sega to form a new studio, Artoon. Sonic Team achieved success in the arcade game market in 1999 with the launch of rhythm game Samba de Amigo, released the following year for the Dreamcast. The studio also began developing online games; in 1999, they released ChuChu Rocket!, a puzzle game that made use of the Dreamcast's online capabilities. In 2000, Sonic