NTT's Next-Generation LLM 'tsuzumi 2' Now Available ~Supporting Japan's corporate digital transformation with a high-performance, high-security, low-cost purely domestic LLM~

TOKYO - October 20, 2025 - NTT, Inc. (Headquarters: Chiyoda, Tokyo; President and CEO: Akira Shimada; hereinafter "NTT") will begin providing the lightweight yet high-performance Japanese processing LLM "tsuzumi 2" on October 20, 2025, aimed at resolving issues such as increased electricity consumption and costs associated with the widespread adoption of large language models¹ (LLMs).

NTT is actively promoting the proposal and implementation of AI solutions that are optimally tailored to public environments, closed environments, and customers' business models and data requirements. To comprehensively enhance its diverse AI proposal capabilities and expand its AI portfolio, NTT has added tsuzumi 2to its lineup.

^* This press release was created using tsuzumi 2.

Background of the Offering

In recent years, while attention to LLMs such as ChatGPT has surged, traditional LLMs-which require massive training data and computational resources-face challenges including increased electricity consumption, rising operational costs, and security risks associated with handling confidential information. In response to these issues, NTT introduced the lightweight yet world-class Japanese-processing LLM "tsuzumi"² in 2023, driving the adoption of AI among domestic companies and local governments.

In actual business environments, we have received numerous requests from corporations and local governments to enhance the ability to understand complex documents they own and to strengthen the capacity to respond to specialized knowledge. By feeding these needs back into R&D, NTT has developed the next-generation model of tsuzumi, called tsuzumi 2. In addition to meeting the performance requirements that address customer needs, tsuzumi 2inherits the existing capability of being able to perform inference on a single GPU, thereby keeping environmental impact and costs low and accelerating AI adoption by corporations and local governments.

Key Features of tsuzumi 2

■ Further Enhancements in Japanese Performance

In terms of Japanese performance, tsuzumi 2achieves world-top results among models of comparable size. In the business domain, where the basic abilities of knowledge, analysis, instruction-following, and safety are prioritized, it delivers performance on par with-or even exceeding-models that are several times larger, while offering a superior cost-performance ratio.

(Figure 1 - Evaluation of Japanese Performance)

■ Improved Efficiency in Specialized Model Development

RAG³ and Fine Tuning⁴ have improved the efficiency of developing domain-specific models for companies and industries. tsuzumi 2has reinforced knowledge in the financial, medical, and public sectors-areas where customer demand was high. As a result, it delivers top-tier performance in those domains and excels in accuracy gains achieved through specialized fine-tuning. In addition, its generic task-specific fine-tuning capability enables versatile use across a wide range of business functions. For example, an internal evaluation at NTT that deployed tsuzumi 2for "financial-system inquiry-handling" showed performance that matches or exceeds that of leading external models, confirming world-class results.

(Figure 2 - Performance Evaluation of LLMs in RAG Use Cases)

■ Low Cost & High Security Maintained - Purely Domestic AI

tsuzumiis a purely domestic model that NTT developed from scratch, starting from zero. It is a lightweight model that runs on a single GPU, offering superior cost performance. Because it can be operated at low cost on-premises or in private clouds, it handles confidential information securely-a key differentiator.

(Figure 3 - GPU Cost Comparison)

Initiatives for Deploying tsuzumi 2

Through AI proposal and deployment activities across NTT Group companies, we have already received numerous inquiries and conducted pre-pilot validations for tsuzumi 2. As a result, two concrete case studies have been realized. Moving forward, we will continue to pursue further deployments across a wide range of industries and domains, aiming to create additional implementation successes.

■ Customer Adoption Track Record

Tokyo Online University has been operating an on-premise, domestic-origin LLM platform that keeps student and staff data within the campus network. After confirming that tsuzumi 2delivers stable performance for complex context understanding and long-document processing, and that it has reached a practical level for composite tasks, the university has decided to adopt tsuzumi 2. The LLM will be used in the following use cases:

With the upcoming full rollout on campus, the university aims to accelerate AI adoption in both educational and administrative domains.

■ Value Creation Through New Collaborations Using tsuzumi 2

NTT DOCOMO BUSINESS Inc., (formerly NTT Communications Corporation; hereinafter "NTT DOCOMO BUSINESS") has partnered with FUJIFILM Business Innovation Corp. (hereinafter "FUJIFILM Business Innovation") to begin exploring the delivery of a new generative-AI solution built on tsuzumi 2.

FUJIFILM Business Innovation operates the AI technology brand "REiLI"⁵, which converts unstructured corporate data-such as contracts, proposals, and mixed text, figures, and images-into structured, actionable information.

By combining tsuzumi 2's high-performance, secure generative AI capabilities with FUJIFILM Business Innovation's data-structuring technology, the two companies aim to create an advanced generative-AI solution that dramatically enhances the analysis and utilization of corporate documents and images.

Through this initiative, NTT DOCOMO BUSINESS and FUJIFILM Business Innovation will strengthen their AI-proposal capabilities and contribute to business transformation and productivity gains for enterprises.

Future Outlook

With the launch of tsuzumi 2, NTT will systematically advance solution offerings and service implementations from across the NTT Group. In parallel, we will pursue applications in the cybersecurity domain and develop AI Constellation that can autonomously collaborate and debate. Through these initiatives, NTT will accelerate the creation of new value and the elevation of the customer experience.

At the NTT R&D Forum 2025 (IOWN Quantum Leap), taking place from November 19, 2025, we will showcase the latest generative-AI solutions built on tsuzumi 2and give attendees the opportunity to experience them firsthand.

[References]

NTT LLM "tsuzumi" - Technical Overview
https://www.rd.ntt/e/research/LLM_tsuzumi.html
NTT R&D Forum 2025 - "IOWN Quantum Leap"
https://www.rd.ntt/e/forum/2025/

[Term Glossary]

¹ LLM: A deep-learning model trained on massive text corpora that can generate human-like text, answer questions, and perform other language-related tasks.

² tsuzumi: tsuzumi^® is a registered trademark of NTT, Inc.

³ RAG (Retrieval-Augmented Generation): A technique that combines external knowledge retrieval with generative AI to produce more accurate and up to date responses.

⁴ Fine Tuning: waThe process of adapting a pre-trained model to a specific domain or task by continuing training on a smaller, task-relevant dataset.

⁵ REiLI: FUJIFILM Business Innovation's AI technology brand focused on converting unstructured corporate documents into structured, actionable information.
https://reili.fujifilm.com/en/

About NTT

NTT contributes to a sustainable society through the power of innovation. We are a leading global technology company providing services to consumers and businesses as a mobile operator, infrastructure, networks, applications, and consulting provider. Our offerings include digital business consulting, managed application services, workplace and cloud solutions, data center and edge computing, all supported by our deep global industry expertise. We are over $90B in revenue and 340,000 employees, with $3B in annual R&D investments. Our operations span across 80+ countries and regions, allowing us to serve clients in over 190 of them. We serve over 75% of Fortune Global 100 companies, thousands of other enterprise and government clients and millions of consumers.