Integrating the clinical presentation, hematologic abnormalities, monoclonal IgG kappa paraprotein with an extreme κ/λ imbalance, elevated β2-microglobulin, bone marrow plasmacytosis, and renal histopathology, the final diagnosis was kappa light chain-restricted IgG MM with biopsy-proven myeloma cast nephropathy, presenting as AKI on chronic kidney disease. Here, HLA-G is linked to Miyoshi myopathy.