Stella AI Adds Anthropic's Latest Models "Claude Sonnet 5" and "Claude Haiku 4.5"

SUPERNOVA Inc. (Headquarters: Minato-ku, Tokyo; President and CEO: Touken Kimoto; hereinafter referred to as "our company"), which develops generative AI services, will begin offering the AI models "Claude Sonnet 5" and "Claude Haiku 4.5" on its generative AI services "Stella AI" and "Stella AI for Biz" starting July 2, 2026 (Wed).

Model Overview

We are adding two Claude models with different characteristics: "Claude Sonnet 5" which prioritizes quality, and "Claude Haiku 4.5" which is fast. By using them according to the application, we can widely cover tasks that require accuracy to those that require speed and volume. Both models can be used without limit. *1

"Claude Sonnet 5" is the highest-performing model in Anthropic's Sonnet series, offering intelligence close to the higher-tier Claude Opus 4.8. Compared to the previous model, "Claude Sonnet 4.6," its accuracy in reasoning and knowledge tasks has improved, and the tendency for factual inaccuracies (hallucinations) and excessive agreement with the user (sycohancy) has been significantly reduced.

"Claude Haiku 4.5" is Anthropic's fastest model. While maintaining a level of intelligence close to higher-tier models, its feature is its quick response, making it suitable for tasks requiring speed and volume, such as customer support, summarization, and classification.

With the addition of these models, "Stella AI" and "Stella AI for Biz" will allow users to select the optimal model for their purpose in daily tasks such as creating business documents, research, and summarization.

Future Outlook

Generative AI technology is evolving daily, with new services emerging one after another. We will maximize the use of the latest technology to provide easy-to-use, high-quality services for our customers, acting as a bridge connecting technology and people to contribute to the realization of a society where no one is left behind.

Company Overview

Company Name: SUPERNOVA Inc.

Headquarters Address: Sumitomo Fudosan Toranomon Tower 19F, 2-2-1 Toranomon, Minato-ku, Tokyo

Representative Director: Touken Kimoto

Business Activities: Development and provision of services utilizing generative AI

Established: January 11, 2024

HP: https://supernova-inc.com

Corporate Inquiries: https://stella-ai.tayori.com/f/stella-ai-for-biz-inquiry

ISO/IEC 27001 Certified (Certification Registration No.: SCC/INT/2505SN/11304)

Privacy Mark Certified (Certification Registration No.: 17005217(01))

Certified Business for Digitalization/AI Introduction Subsidy 2026

* "Stella AI" and "Stella Craft" are trademarks or registered trademarks of SUPERNOVA Inc.

* Other company names and product/service names mentioned in this press release are registered trademarks or trademarks of their respective companies.

*1: Claude Sonnet 5 and Claude Haiku 4.5 have been added to the Claude Unlimited Campaign, and Claude Sonnet 4.6 will no longer be eligible. This campaign will end at the end of July 2026.

SUPERNOVA is recruiting individuals who will be at the forefront of generative AI, driving the evolution of products and society.

▶ Customer Success: Supporting the success of client companies from the front lines.

▶ Engineers: Implementing AI functions from 0 to 1 using cutting-edge technology.

Please contact us at hr@supernova-inc.com.