This study outlines a comprehensive analysis of word-formation models of the Japanese youth sociolect as the most active channel for the creation and dissemination of linguistic innovations. Youth word formation 「若者語の造 語法」 [wakamonogo no zougoho] is considered in the article from the point of view of deviations from the established norms of the common Japanese language, which has its own rules of word formation and is based on a creative approach with the involvement of common language resources. Word formation, as a source of replenishment of youth vocabulary, has nominative and emotional-expressive functions. For the first time, an attempt is made to systematise lexical items of the youth sociolect in accordance with the word-formation structure of the Japanese language. The study reveals and analyses the sequences in the word formation system of the youth sociolect in comparison with the sequences of the normative system of the Japanese language. The ways of word formation in the youth language and the degree of their productivity are investigated, focusing on the morphological and lexical-semantic productive levels of word formation, with examples of actual/real use. The analysis of the factual material has shown that the most productive ways of youth word formation are word-formation models at the morphological level: abbreviations, affixal word formation, English borrowings, word compounding, word-formation techniques of “word play”; and at the lexical and semantic level: metaphors and metonymy. The high productivity of the above word-formation forms of the Japanese youth sociolect is explained by the simplicity of deformation of words that create a stylistically understated effect and carry an emotional and evaluative component in their structure. The analysis of the word formation of the modern youth sociolect is quite appropriate and promising in predicting the process of change and enrichment of the normative Japanese language. The systematisation of youth word formation methods opens up new perspectives in the study of word formation innovations and expands the understanding of the linguistic picture of the world of modern Japanese youth.