Treatment trends for newly diagnosed multiple myeloma (NDMM) are not fully evaluated in real-world settings in the Japanese population. Triple-class exposed (TCE) patients with relapsed or refractory MM have a poor prognosis and limited treatment options. To clarify characteristics, treatment trends, and TCE status in Japanese patients with MM, we conducted a retrospective, non-interventional study. Data from patients with MM were extracted from a Japanese claims database between 2015 and 2022: this study identified patients with NDMM prescribed daratumumab (D), lenalidomide (R), and/or bortezomib (V) as 1st-line treatment. The patient characteristics and treatment trends were analyzed for non-transplant and transplant groups. Of 1,784 patients, non-transplant patients (n = 1,656, median age 75 years [range: 37–94]) received R+dexamethasone (Rd) (24.7%), Vd (23.8%), and RVd (15.6%) and transplant patients (n = 128, median age 61 years [range: 35–73]) received RVd (49.5%), Vd (18.7%), and DVd (8.4%) in 1st line. In the non-transplant group, the commonly prescribed treatment regimens were Rd for patients aged ≥75 years, Vd for patients aged 65–74 years, and RVd for patients aged <65 years. Patients with renal or cardiac dysfunction commonly received Vd or Rd, respectively. In the transplant group, 107 (83.6%) and 20 (15.6%) patients received transplantation in the 1st and 2nd lines, respectively. The top three regimens as induction therapy before stem cell transplantation were RVd (49.5%), Vd (18.7%), or DVd (8.4%) in 1st line. Cumulative TCE patients by 5th line were 351 (21.2%) and 56 (43.8%) for non-transplant and transplant patients, respectively. TCE ratio at each line gradually increased from 1st to 5th line (11.1–69.2% in the non-transplant group and 21.1–100% in the transplant group, respectively). Of 184 TCE patients in the non-transplant group, 89.7% received sequencing treatments including DRd, RVd, and DVd, and 10.3% received D-RVd in 1st line.