Herpes simplex virus (HSV) hepatitis has a fatal impact on the outcome of organ transplanted recipients. Here, we present a thought-provoking case of HSV hepatitis in a high-risk recipient after living-related liver transplantation (LRLT). A 1-month-old female newborn infant was affected by HSV encephalitis. Fulminant hepatic failure (FHF) of unknown etiology occurred suddenly at 4.4 years of age. Viral infections were ruled out as the cause of FHF. Intensive care including plasma exchange (PE) was started, and the preoperative treatments for ABO incompatibility were performed. Thereafter, LRLT was performed emergently. Although strong immunosuppression for ABO incompatibility was continued after LRLT, antibody-mediated rejection (AMR) occurred on postoperative day (POD) 4. PE was repeated and improvements were obtained. However, liver dysfunction appeared on POD 8. Histopathological findings of liver needle biopsy clearly revealed HSV hepatitis, although the results of HSV DNA and antibody titer in blood sample did not clearly indicate HSV infection. On POD 21, thrombotic microangiopathy (TMA) occurred and the plasma and immunoglobulin were replenished. Our pediatric recipient recovered successfully from AMR, HSV hepatitis, TMA, and repeated sepsis. We conclude that well considered therapy based on the real-time detection of HSV hepatitis is indispensable for the further improvements of outcome in HSV hepatitis after LRLT.