№ 01 · A solo studio from Obi, southern Kyushu

Small apps, made slow.
Software that doesn't want your day.

A solo studio in Obi, run by Jérôme Sadou — quietly making small things since 2010. First for clients, now for the studio's own products.

EST.2010
LOCATION宮崎県日南市飫肥
PEOPLESolo
CLIENTSClosed · 2020
06:14 · sunrise, today sun · #F0D670 sky · #6E95B8

Ohayo (おはよう) is the Japanese word for good morning. It implies the time before anything has happened yet — the quiet bit at the start of the day, before the noise.

I build small, focused apps — the kind that do one thing well and then get out of the way. Not the kind that wants your attention, your streaks, your push notifications, or your seventeen minutes a session.

After ten years of client work, I stopped taking clients in 2020. My day job since then has been engineering at a medical-field company. Ohayo runs quietly on the side, and Pokeibo is the first product to ship from it.

— Jérôme Sadou
№ 03 · Products

Things we made on purpose.

COMING · 2 LAUNCHES
both late July 2026
Launch · late July 2026

Pokeibo

A household-expense tracker that stays on your phone. Import your PayPay Card CSV once a month and watch your spending sort itself by merchant. No accounts, no bank linking, no streaks, no nagging — your data never leaves the device.

PLATFORMiOS · Android
LANGUAGESJP · EN · ZH
PRICE¥299/mo · ¥1,800/yr
Pokeibo — home screen
Launch · late July 2026

Sepia Braun

A personal publication about things worth paying attention to — objects built to last, food that took years to perfect, design that justifies itself without shouting, and corners of Japan that don't show up on the first page of results. Slow, deliberate, written from a single point of view. Named after Porsche colour code 415.

FORMATWeb · RSS · Newsletter
VOICEOne human, in Japan
POLICYNo ads · no tracking
Vol. I Japan, slowly
Things
that stayed.
Objects, food, design, and Japan — chosen because they're worth a few hours of attention. One voice, no tracking.
Sepia Braun 415 · since 2025
№ 04 · Lab

The workshop behind the apps.

Tools we built for ourselves and then shared.

Flagship Rails 8 · MIT

Edo-cms

The Rails 8 template we fork into every Ohayo site — including this one.

A Rails 8 content template. Brand identity — palette, fonts, logos, navigation, copy — lives in a single Setting record, editable from /admin. Fork it, rebrand from the admin, deploy. Quietly opinionated about typography, bilingual content, and slow software.

Rails 8 · Solid stack · no Redis
Brand config from /admin · no code
Hotwire · Tailwind v4 · ViewComponent
Lexxy rich text + Active Storage
Bilingual routing (EN / JA)
Kamal deploy + fork workflow
~/sites/my-site bin/setup
bundling …………………… 287 gems · ok
database ……………… create + migrate · ok
seeding ……………… 5 articles + 5 videos · ok
✓ ready in 12s
 
~/sites/my-site bin/dev
web → http://localhost:3005
css ◌ watching tailwindcss…
app/views/admin/brand config UI
app/models/setting.rbidentity model
config/locales/en.ymlen + ja labels
db/seeds/demo content
№ 05 · The studio

Solo studio,
one old samurai town.

Run by Jérôme Sadou from Obi — a quiet former castle town in southern Kyushu, sometimes called the Little Kyoto of Kyushu (九州の小京都). A guy who likes the outdoors but ends up in front of his Mac more than he'd care to admit.

More on the person at jeromesadou.com/apropos. If you'd like to write — about the work, the products, or a problem you'd like a small app to quietly solve — please do.

Journal · RSS
Mail · Post
宮崎県日南市飫肥
DISTRICT飫肥 · Obi
CITY日南市 · Nichinan
PREFECTURE宮崎県 · Miyazaki
CASTLE飫肥城 · since 1588
TIMEZONEJST · UTC+9
SIZESolo