In 1985 Ueno also reformed Guernica and the group issued its 2nd CD titled “shinseiki eno unga” (canal to the new century) in July 1987.
During 1986-1987 Ueno also worked with Ryuichi Sakamoto on the scores for the movies “koneko monogatari” and “oneamisu no tsubasa”. He also worked alongside Sakamoto on the soundtrack score for the award winning movie “Last Emperor”. In 1987 Ueno became involved with the Tokyo based ballet company "Tutuland Academy" lead by English choreographer Nicholas Dixon. He premiered his first ballet suite entitled “The Headcracker” that same year, and continued to work with “Tutuland Academy” for the next 3 years. A double CD compiling Ueno's works for "Tutuland Academy" appeared in 1993.
In 1989 Ueno received the prize for best music at that years Mainichi Film Festival for his musical score for the film "Untama Giru". The score itself was based around themes involving traditional Okinawan folk musics. Guernica also reformed again that year, touring and recording a third CD entitled ‘denriso karano manazashi’ (the regard from ionosphere).
In 1990 Ueno was commissioned to score traditional songs for vocals and classical chamber ensemble for the National Theater of Japan. In 1992 he was commissioned by “Pro Musica Japonia” (an ensemble of various japanese instruments) to produce works on their behalf. The same year he also composed a piece for “Paul Dresher” ensemble of San Francisco, performed by them at the 1993 interlink festival. Never a man to neglect new media, Ueno also composed the music for an interactive CD-ROM entitled "GADGET", which won the top prize in 1993 at Japan's AVA Multimedia Grand Prix. 1994 saw Ueno have a performance of several of his main works as "the world of Koji Ueno" at "Tokyo no Natsu" a music festival organised by the prestigious Arion Music Foundation. A further accolade arrived in 1995, when he won the prize "Cristal tcheque pour la musique contemporaine”, at the 32e International Television Festival held in Prague for his soundtrack made for the NHK TV drama “The Pale Cast of Thought".
In 1997 Ueno formed a new project entitled "netsuzo to' gansaku” (fabrications and counterfeits) with long time friend and former "eight and a half" vocalist: Shingo Kubota. Their debut CD was released in 1998, and was another return to the early electronic programming methods developed by Ueno, rather than works specifically scored for ensemble or solo performance. Their first CD also included new versions of several pieces originally debuted on Keiichi Ota’s 1983 recording “Jingaidaimakyo”. Ueno also made sure that many of his earlier works for Guernica were not forgotten, when in 1998 he rearranged several songs for performance by classical singers. In 1999 a CD compiling a number of his early works as solo piano pieces was also released on Zen-on music. During the year 2000 Ueno began lecturing in film music at the Art Faculty of the Tokyo based Nihon University. He also began to experiment with freeform Jazz and classical music fusions through a new project entitled the Koji Ueno Trio, where he was joined by Takayoshi Matsunaga (bass, ex-mute beat) and Tomo Tsuruya (drums). Their first CD release (ionospheric call) appeared that same year.
prix "Cristal tcheque" pour la musique contemporaine, 32e festival international de television "Prague d'or" (1995),
music prize in festival des trois continents - Nantes (1989),
music prize in mainichi film concours (1989).
