High-Precision Industrial Translation AI 'T-4OO' Achieves 0.05% Revision Rate in Contracts with 'Ultra-High Precision (Deliberation)' Mode

Rozetta Inc. (CEO: Junichi Itsutsuishi), a company under the Metalial Group developing and providing Japan's No.1 AI translation service※ in the domestic market, announces on June 17, 2026, that its high-precision industrial translation AI 'T-4OO (T-Four-O-O)' has achieved a revision necessity rate of 0.05% (sentence-based) in the field of contracts using the 'Ultra-High Precision (Deliberation)' mode, which leverages agentic AI.

Contract translation has traditionally required full-document review—comparing each sentence of the original and translated text—because mistranslations directly lead to legal risks. With this achievement, the level has now been reached where review can shift from full-document checks to targeted verification of flagged sections. This marks the second domain, following user manuals and instruction guides, where this milestone has been achieved, advancing the company's vision of 'human-editing-free translation AI.'

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■ What is the 'Ultra-High Precision (Deliberation)' Mode?

The 'Ultra-High Precision (Deliberation)' mode, added to 'T-4OO' on April 13, 2026, is a translation mode equipped with agentic AI. In addition to translation quality surpassing the conventional 'High Precision' mode, it features an AI-driven quality assessment system that:

- Highlights sections identified as potentially mistranslated

- Displays suggested alternative translations and comments for those sections

Users can instantly see which parts of the translation require review or correction, allowing them to replace time-consuming full-document checks with targeted verification of flagged areas. Furthermore, the quality assessment incorporates the user's registered terminology databases and past bilingual data, enabling checks that leverage the company's accumulated translation assets.

■ Verification Results in Contract Translation: 0.05% Revision Rate

Internal verification was conducted on contract documents (including service agreements, non-disclosure agreements, sales contracts, license agreements, share transfer agreements, etc., commonly handled by legal and IP departments). The results showed a sentence-based revision necessity rate of 0.05%. This matches the previously announced 0.05% rate in the user manual and instruction guide domain (announced April 13, 2026), demonstrating that even in documents like contracts—where every word and phrase directly impacts legal risk—human review can now be limited to flagged sections only.

【Verification Conditions】

Target: Contract domain (service agreements, NDAs, sales, licenses, share transfers, etc.)

Language Pair: Japanese → English

Unit: Sentence-based

Mistranslation Criteria: Only clear, objective mistranslations visible to any observer (subjective disagreements excluded)

Excluded: Text extraction accuracy from files, layout reconstruction accuracy (only text-to-text translation accuracy evaluated)

Note: In addition to source and target text accuracy, adherence to reference documents is considered (not classified as mistranslation if not verbatim but not erroneous)

Reference: A 0.05% revision rate corresponds to approximately one sentence per 100–200 pages

■ Changes Brought to Contract Translation Workflows

Achieving a 0.05% revision rate in contract translation enables users to experience the following operational improvements:

- Transition from full-document review to targeted verification of flagged sections

- Potential mistranslations are highlighted with comments, making review focus clear at a glance

- AI can verify whether translations align with internal terminology databases and bilingual data

- Past contract translation assets can be leveraged to ensure consistent translations across documents

This enables simultaneous improvement in translation quality and reduction in workload for legal, IP, and compliance departments.

■ Comment from T-4OO Development Lead, Atsunori Shinoda:

"When we launched on April 13, 2026, we disclosed verification results for the 'Ultra-High Precision (Deliberation)' mode in the user manual and instruction guide domain (0.05% revision rate). We are delighted to now report achieving the same level of translation accuracy in the contract domain. Contracts are documents where even minor mistranslations or inconsistencies in expression can directly lead to legal risks, and until now, rigorous full-document manual review has been the de facto standard. This result demonstrates that the quality assessment and alternative suggestion mechanism powered by agentic AI functions effectively not only for manuals but also for highly precise documents like contracts, enabling review to be limited to flagged sections. We will continue verification in other domains such as pharmaceutical and medical documents, patent documents, financial reports, and IR materials, striving toward the realization of our vision: a 'human-editing-free translation AI.'"

■ Comment from T-4OO User, Attorney Tatsuki Nakayama, Nakayama International Law Office:

"As the head of an international law firm, I frequently need to translate large volumes of documents while maintaining confidentiality. I've been a long-time user of T-400 and now serve as a translation advisor, providing feedback on performance improvements. The new 'Ultra-High Precision (Deliberation)' mode has significantly improved usability, not only enhancing translation quality but also clearly indicating potential mistranslations at a glance. As a legal expert conducting final reviews of machine-translated texts, I can now place much greater trust in translations produced by this mode, greatly reducing my workload. Previously, when I noticed awkward machine-translated output, I had to manually verify whether the issue was in the original text or the translation. Now, the 'Ultra-High Precision (Deliberation)' mode proactively flags these inconsistencies, saving me significant time in reviewing the original text line by line."

■ Future Outlook

T-4OO will continue sequential verification in other specialized domains, including pharmaceutical and medical documents, patent documents, financial reports, and IR materials, and will publicly announce results. These verifications are part of the company's efforts toward achieving its vision of 'human-editing-free translation AI.' Based on user feedback, we will continue improving functionality and user experience to further shift translation workloads from full reviews to targeted verification of flagged sections.

【About T-4OO (T-Four-O-O)】

T-4OO is a high-precision industrial translation AI that combines customization capabilities for reproducing specialized documents and internal terminology with the fluency of generative AI. Unlike traditional industrial or specialized translation tools, T-4OO offers a 'High Precision' mode that accurately reflects translation style and expression by leveraging internal translation assets—without requiring users to build expensive dedicated engines—and an 'Ultra-High Precision (Deliberation)' mode powered by agentic AI, which has received high praise for its dramatically improved translation accuracy.

High-precision, terminology-strong industrial translation AI 'T-4OO': https://www.rozetta.jp/t4oo/

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