Bridging National and International Legal Data: Two Projects Based on the Japanese Legal Standard XML Schema for Comparative Law Studies

TL;DR

This paper introduces a framework that connects Japanese legal data with international standards and employs multilingual models to identify and visualize cross-jurisdictional legal provisions for comparative law research.

Contribution

It develops a conversion pipeline from Japanese Legal Standard XML to Akoma Ntoso and applies multilingual embeddings for cross-national legal provision matching.

Findings

Successful conversion pipeline from JLS to AKN established

Prototype system effectively identifies and visualizes legal provision correspondences

Enables comparative law analysis across jurisdictions

Abstract

This paper presents an integrated framework for computational comparative law by connecting two consecutive research projects based on the Japanese Legal Standard (JLS) XML schema. The first project establishes structural interoperability by developing a conversion pipeline from JLS to the Akoma Ntoso (AKN) standard, enabling Japanese statutes to be integrated into international LegalDocML-based legislative databases. Building on this foundation, the second project applies multilingual embedding models and semantic textual similarity techniques to identify corresponding provisions across national legal systems. A prototype system combining multilingual embeddings, FAISS retrieval, and Cross-Encoder reranking generates candidate correspondences and visualizes them as cross-jurisdictional networks for exploratory comparative analysis.