About Eichan & Jolly

Who we are

Eichan is a one-person business in Japan that experiments with generative AI in real work and daily life — and sells the tools that survive the experiments. Jolly is the cream-colored plush partner (no ears, no feet, no doubts) who fronts the shop, checks the shelves and appears wherever a page needs a guide.

What we make

Small, single-purpose AI tools: prompts and agent skills that do one job from your facts, Notion templates that run a small business, and books about working with AI without losing the thread. Everything is sold under the name Eichan on marketplaces; this site is the duo's home.

How we work

The human picks the problem, makes the decisions and does the final check. AI does the production work. Before anything is listed, a fresh-context reviewer — an AI that did not build the product — executes it adversarially, including attempts to make it invent numbers, dates or quotes. Products that fail are fixed or dropped, never shipped anyway.

Our rule for “easy to use”

A tool that only makes sense to its maker is maker's ego, not a product. If a beginner, seeing it for the first time, can't understand and use it as-is, that is a defect — and we fix it before we sell it.

Follow along

Day-to-day experiments (in Japanese) live on note and X @hey_eichan. The shop's English channels are in the footer of every page.