Hirofumi focused on enhancing documentation quality and code readability across major open-source repositories, including Next.js, Tailwind CSS, PyTorch, LangChain, Django, Matplotlib, and Flutter. Over two months, Hirofumi systematically corrected grammar, spelling, and style issues in Markdown, Python, and YAML files, improving onboarding and maintainability without altering code behavior. In flutter/flutter, Hirofumi refined configuration comments to aid contributor understanding, while in vercel/next.js and tailwindlabs/tailwindcss, Hirofumi addressed documentation clarity and consistency. The work demonstrated attention to detail and adherence to repository standards, leveraging skills in Python, Django, and testing to deliver precise, traceable improvements across diverse codebases.