While exports of oysters from Japan are increasing in recent years, it is necessary to establish a pre-export testing implementation system in Japan using ISO 15216 method, which is used internationally as a testing method for norovirus in oyster. However, NucliSENS miniMAG (bioMérieux), an RNA extraction device widely used in Europe, has already been discontinued and is not available in Japan. In this study, we verified the substitutability of Mealstrom 8 (TANBead) as an alternative suggested in a previous report, using pacific oyster (Crassostrea gigas), which is commonly consumed in Japan. Moreover, we verified the substitutability of the three reagent kits available in Japan for RNA UltraSense one-step quantitative RT-PCR system (Thermo Fisher Scientific), which is the reagent recommended by the official protocol of ISO 15216 method. As a result, viral RNA was extracted more efficiently by Maelstrom 8 than by the NucliSENS miniMAG. And of the three reagent kits, CEERAMTOOLS noroGI–GII@ceeramTools (bioMérieux) was shown to have the same performance of gene detection as UltraSense. These results are expected to contribute to establishment of the pre-export testing system for oysters using ISO 15216 method in Japan.