The complete mitochondrial genome (mitogenome) of the Inimicus japonicus was analyzed by nextgeneration sequencing in this study. The mitogenome is 16,978 base pairs (bp) long and codes for 22 transfer RNA (tRNA) genes, 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNA), and 1 noncoding control region. The overall nucleotide composition of the mitogenome is: 29.61% for A, 29.16% for T, 25.26% for C, and 15.97% for G. Twenty-two tRNAs range from 67 to 74 bp in length, and 2 rRNA (12S and 16S) were 953 and 1,687 bp long, respectively. Phylogenetic analysis by neighbor-joining (NJ) method indicated that I. japonicus showed considerable genetic similarity (82%), and had a closer relationship in the phylogenetic tree to Synanceia verrucosa.