A man in his 60s with a large Type 3 gastric cancer presented with the chief complaint of epicardial discomfort. We decided to perform laparoscopy. The patient was diagnosed with cT4aN2M1(CY1), cStage Ⅳ disease and was treated with XP(capecitabine plus cisplatin[CDDP])plus trastuzumab(HER). After chemotherapy, CY0 was confirmed using laparoscopy. The patient underwent total gastrectomy and D2 lymph node dissection. Histopathological examination revealed ypT4aN3M0, ypStage ⅢC disease. Therefore, adjuvant treatment with XP plus HER was continued. Four months after surgery, liver, lung, and # 16b1latLN metastases were observed on CT. The metastatic foci were observed even after 3 courses of ramucirumab plus paclitaxel. Nivolumab was administered as the third-line treatment; after 3 courses, the liver metastasis increased markedly. Hence, our final diagnosis was hyperprogressive disease(HPD).