Twelve years ago our 4-person Tokyo studio built the app called "feather for Twitter", once #1 in Japan’s App Store, until Twitter’s API shutdown.

Jan 2025: we pivoted to B2B. Eyes Mail’s MVP let GPT-4 craft subject-line variants and auto-optimize opens/CTR.

Users? They uploaded a CSV, hit Send all, and ignored the AI wizard. Bulk email is grunt work—speed beats “smart.”

So we cut 70 % of the code and rebuilt Eyes Mail as one page: upload → write → send → instant report. Tasks fell from minutes to ~30 s.

With friction gone, customers asked real questions (“Which segments convert?” “Can AI draft follow-ups?”), so we spun up Eyes Analytics: merges mail + web data and calls AI only when you ask.

What we learned → Half-baked AI hurts; make the boring path blazingly fast first.

Happy to answer anything, tech stack, Japan-specific SaaS hurdles, etc.