Seonghyeon Kim developed localization support for the 'Custom sample sets' label in the FormSampleSetChooser component within the ppy/osu repository. By integrating localized strings and establishing an internationalization-ready UI pattern, Seonghyeon enabled the interface to support multiple languages, laying the groundwork for broader accessibility and future translation efforts. The work focused on C# development and UI engineering, ensuring clear commit-level traceability and maintainable code structure. Although no major bugs were addressed during this period, the feature improved the user experience for non-English speakers and demonstrated a methodical approach to introducing localization into an existing C# application’s user interface.