SoftBank Corp. and enterprise artificial intelligence startup Sierra have formed a strategic partnership to introduce AI agent-powered customer experiences across Japan, with SoftBank becoming Sierra’s exclusive partner in the country from July 14, 2026. The agreement combines Sierra’s conversational AI platform with SoftBank’s enterprise network, market reach, and experience serving Japanese companies. The partnership aims to accelerate AI agent adoption in customer service while improving operational efficiency, service quality, and customer satisfaction.
New AI Offering for Japanese Enterprises
Under the collaboration, SoftBank will offer Sierra’s platform to Japanese companies seeking to modernize customer-facing operations with autonomous AI agents. Sierra will design, deploy, and optimize agents tailored to each organization’s brand guidelines, business rules, internal knowledge, and operational requirements. SoftBank will support the rollout through its extensive enterprise customer network and its broader strategy to expand the practical use of artificial intelligence across Japan.
Beyond Automated Customer Responses
Sierra’s platform is designed to do more than generate answers to customer questions, allowing its agents to complete follow-up actions such as processing returns and handling administrative procedures. The goal-oriented agents interpret inquiries, determine the steps required for resolution, and carry out relevant tasks from the initial interaction through completion. Companies can also deploy the technology across customer support, sales, and back-office functions while adapting the agents to their own service standards.
SoftBank Reports Early LINEMO Results
SoftBank has already used Sierra to develop customer support agents for LINEMO, its online-only mobile brand, providing an early test of the technology in Japan. According to the companies, the deployment increased the inquiry resolution rate from 83% under the previous service to 97%, while customer satisfaction rose from 74% to 93%. Based on those results, SoftBank plans to evaluate Sierra for its SoftBank and Y!mobile brands, along with other services operated by group companies.
Continuous Improvement Across Voice and Text
Sierra’s platform continuously improves its agents by analyzing customer conversations and inquiries across integrated voice and text channels. This approach is intended to raise response quality and help enterprises adjust automated services as customer expectations, products, and internal processes change. By combining autonomous task execution with ongoing optimization, the technology seeks to provide more consistent support than traditional question-and-answer chatbots.
Partnership Supports Broader AI Strategies
SoftBank President and CEO Junichi Miyakawa described AI agents as a transformative technology capable of reshaping how companies interact with customers. Sierra co-founder and CEO Bret Taylor highlighted Japan’s reputation for high service standards, noting that the concept of anticipating customer needs has influenced Sierra’s platform development. The agreement also supports SoftBank’s “Activate AI for Society” growth strategy, which includes expanding AI infrastructure, cloud services, and next-generation digital capabilities.
Commercial Significance in Japan
The partnership gives Sierra a major distribution and implementation partner in one of Asia’s most important enterprise technology markets. Sierra says its platform is used by 40% of Fortune 50 companies, one-third of the world’s leading banks, and major global telecommunications businesses. SoftBank can use that existing enterprise experience to present the technology as a proven solution rather than an experimental AI product.
SoftBank and Sierra’s partnership represents a significant effort to move AI agents into everyday enterprise customer service operations in Japan. Early results from LINEMO provide a measurable case for broader deployment, although adoption across additional brands and industries will determine the collaboration’s longer-term impact. By combining Sierra’s agentic AI technology with SoftBank’s domestic reach, the companies aim to make autonomous and personalized customer support more accessible to Japanese businesses.