Oakleaf butterflies in the genus Kallima have a polymorphic wing phenotype, enabling these insects to masquerade as dead leaves. By studying mechanisms that shape the genetic and species diversity of these butterflies, a new perspective can be provided to understand the evolutionary innovation driven by geographic changes and natural selection. We found that leaf wing polymorphism in Kallima butterflies is controlled by the wing patterning gene cortex. We hypothesized that multiple mechanisms may independently lead to the reduction or suppression of recombination among different cortex haplotypes. To test this hypothesis, we performed Nanopore re-sequencing and de novo genome assembly for 4 Kallima inachus individuals and obtained 4 individual genomes. We identified two chromosomal inversions spanning these haplotypes. For Nanopore sequencing, genomic DNA was isolated from adult butterfly thoracic tissues from individuals representing the veined, scrambled, rippled, and moldy wing forms. The long-read Nanopore sequencing library was prepared using a SQK-LSK109 Ligation Sequencing Kit and sequenced on the Nanopore promethION platform at GrandOmics. Low-quality Nanopore sequencing data were filtered from raw reads using Nanofit v2.3.0. De novo genome assembly was performed using NextDenovo v2.2-beta.0 (https://github.com/Nextomics/NextDenovo), and base errors were further corrected with Illumina sequencing data using NextPolish v1.1.0. Here shows the sample information of the 4 Kallima inachus individuals. The raw sequence data are available from the NCBI Short-Read Archive (SRA) database (accession numbers PRJNA698433).