This repository is the canonical source data for the ZenginCode ecosystem, providing a curated, machine-readable dataset of Japanese bank codes and branch codes. It contains structured branch information (code, name, kana, hira, roma) for thousands of financial institutions across Japan, stored in both JSON and YAML formats under data/branches/. The data is automatically updated daily via a GitHub Actions workflow that downloads the official Zengin bank branch list from an external source, converts it from Shift_JIS CSV to UTF-8, and generates per-bank branch files. The repository also includes a Ruby CLI tool (bin/zengin) that orchestrates the download, conversion, and commit process, making the pipeline reproducible. While primarily a data repository, it includes a well-structured ETL pipeline that can serve as a template for similar data curation projects. The dataset is consumed by language-specific packages (Ruby, JavaScript, Python) to provide bank branch lookup functionality in financial applications.