Short answers, pulled from the story.
Yoko Ueno performed in the Japanese pop-rock band Oranges & Lemons, the group Vita Nova, the band Marsh-Mallow, and Zabadak. These early collaborations established her reputation as a versatile vocalist capable of adapting to different rock styles.
Her first solo album Voices arrived on the 5th of December 1993 through Biosphere Records. This release marked her transition from band member to independent artist.
Ueno adopted the name asterisk to explore different musical directions separate from her main artist identity. The use of the symbol created a distinct brand for these particular collections of songs while allowing fans to recognize the shift in style when they encountered music labeled as asterisk instead of Yoko Ueno.
Yoko Ueno contributed to Brigadoon Marin-To-Meran Original Sound Track 2 on the 24th of January 2001 and .hack//tasogare-no-yubiwa-densetsu original sound track released the 21st of February 2003. She worked with Yuji Yoshino at Victor Entertainment on both projects.
A special live recording titled YK20[audio] marked twenty years since her debut in 1987 and was recorded for release on the 4th of March 2007 through tilde disc. A visual counterpart DVD named YK20[visual] followed on the 25th of March 2007 also distributed by tilde disc.