There he lived, beside the Dōtonbori entertainment district, among geisha, prostitutes, wig-makers, and gamblers, as he attended Rikugun elementary school from 1899 to 1901.
In 1910 he moved to Tokyo to study English literature at Waseda University, where he read Symbolist poetry and Russian modernists including Leonid Andreyev, Mikhail Artsybashev, Konstantin Balmont, Aleksandr Kuprin, Fyodor Sologub, and Boris Konstantinovich Zaytsev.
At age 28, Uno published his first major work, "In the Storehouse", whose colloquial and ironic style was criticized as "flippant" and "popular".
He received the Yomiuri Prize in 1950 for his 1948 novel Omoigawa (思ひ川, River of Thought), and highly praised for his 1951 critical biography of author Ryūnosuke Akutagawa.
In 1953 he campaigned for the release of twenty Communist factory workers accused of sabotaging a Japan National Railways freight train, publishing two novels on their behalf, and touring China in 1956 on a personal invitation from Zhou Enlai.