We retrospectively analyzed the clinical features and outcomes in a real-world cohort of adolescents and the young adult (AYA) patients (age between 16 and 39 years) with symptomatic multiple myeloma (MM) registered with the Kansai Myeloma Forum. 26 patients had been diagnosed as symptomatic MM out of 3284 patients. The prevalence of AYA-MM was 0.8% in this cohort. 81% of the patients was received stem cell transplantation, which may improve outcome. Anemia and hypercalcemia might be prognostic factors, however International Staging System failed to predict overall survival. Five patients developed late-onset adverse events which were serious and life-threatening. The 5-year overall survival was 71.0%. We need to develop the new strategy to overcome AYA-MM.