Japanese users struggle with AI tools that misunderstand keigo (polite speech) or lack support for local payment methods like PayPay. A locally tailored chat interface could dominate this niche.
Train a model on Japanese business documents and integrate domestic payment processors. Monetize via subscriptions with yen billing.
Start with a web wrapper around open-weight models, then fine-tune for verticals like customer service.
The risk is OpenAI rolling out better Japan support first.