He was studying alongside his future wife Yulia Levteri (they got married in 1936 and gave birth to Gubarev's only daughter Valeria who served as a prototype for the main character in his Kingdom of Crooked Mirrors novel).
At the age of 14 he published his first short story "Rotten Tree" in a local children's magazine.
[6] In 1963 Aleksandr Rou adapted it into a movie Kingdom of Crooked Mirrors with Gubarev serving as a screenwriter.
It was named "Best children's film of 1963" at the all-Union poll conducted by the Soviet Screen magazine, while the title "Kingdom of crooked mirrors" itself turned into an idiom.
[5][7] During later years Gubarev published a number of other popular fantasy books such as a comedy The Three on Island (1959) adapted as a 1986 cartoon, a children's science fiction novel Adventure to the Morning Star (1961) and a fairy tale In the Far Far Away Kingdom (1970) adapted as a movie of the same name (director Evgeny Sherstobitov).