SoftBank Corp. and SB Intuitions Launch
"Sarashina mini" API for Enterprise Use

SoftBank Corp. ("SoftBank") and its subsidiary SB Intuitions Corp. ("SB Intuitions") announced they will begin offering "Sarashina API," a service that enables enterprise customers to connect to the homegrown large language model (LLM) "Sarashina mini" on November 28, 2025.

Sarashina mini is a lightweight model developed by SB Intuitions based on its expertise gained from building the 460-billion-parameter homegrown LLM "Sarashina," delivering high Japanese-language performance and a deep understanding of Japan's unique culture and business practices. The newly announced Sarashina API consists of two key functions: the Chat Completion API^*1, which enables AI to generate natural text, and the Embeddings API^*2, which allows AI to understand semantic relationships within text and extract related information. Enterprise customers can use the Sarashina API to connect their systems and applications with the Sarashina mini API, leveraging internal knowledge to proofread and summarize documents, automatically generate reports, meeting minutes, and proposals, assist programming tasks, and develop conversational or multi-agent systems where multiple AIs collaborate to solve problems. SoftBank and SB Intuitions aim to further enhance Sarashina mini to enable its use in a wider range of advanced business domains, including automated call-center response systems and sales support tools.

SB Intuitions has been advancing the development of homegrown LLMs with high Japanese-language performance and has released several models for research use. To prepare for the commercialization of Sarashina mini, SoftBank and SB Intuitions conducted internal trials at SoftBank involving approximately 20,000 employees beginning in June 2025 to refine and enhance the model.

SoftBank and SB Intuitions will begin offering Sarashina mini to enterprise customers and gradually expand its availability to a wider range of users. In addition, the two companies will develop industry-specific Japanese LLMs to deliver tailored solutions that meet the diverse needs of various businesses and sectors.

[Notes]

1. *1
   Chat Completion API: Enables natural dialogue and text generation using large language models (LLMs).
2. *2
   Embeddings API: Converts text into numerical vectors, allowing AI to understand semantic relationships and similarities between pieces of text.

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