A 34-year-old man developed redness and swelling of his right thigh anterior compartment with fever in October 2024. The closed and deep effusions by active exploratory incision/debridement on hospital days one to three yielded the presence of Gram-positive cocci, although two sets of blood cultures upon admission revealed no bacterial growth; its species identification results indicated S. pyogenes. Clinical and pathological diagnosis was streptococcal SM NTSI (without toxic shock syndrome (TSS)). Negative pressure wound therapy with instillation and dwelling (NPWTi-d) to promote his soft tissue cure was performed along with antimicrobial regimens. The patient recovered and received micrografting (carrier: artificial dermis made from collagen sponge and silicon film, Pelnac Gplus® (Gunze Limited, Osaka, Japan) using the Rigenera® system (Rignera HBW, Candiolo, Italy). Thereafter, he developed bronchitis: the sputum yielded S. pyogenes growth: he recovered uneventfully. Split-thickness skin grafting (STG) was performed. Split-thickness skin grafting was fully engrafted, and the wounds achieved complete healing. The patient could walk by himself. Microbiological genetic analyses using both DNAs from effusion/sputum-origin strains revealed the emm1.0 and speA-speB-smeZ profiles. rofA-gldA-pstB sequencing results indicated M1UK-specific single-nucleotide polymorphisms. The streptococcal inhibitor of the complement-mediated lysis gene allele was the streptococcal inhibitor of the complement-mediated lysis-1.02 allele. Micrografting using the Rigenera® system and STG following NPWTi-d can be beneficial approaches.