hanaco Weather is a minimalist social network where users post short, emotional weather thoughts and connect with others experiencing the same weather.

No likes or followers (for now) — just gentle presence.

Built entirely by a solo engineer, including the custom operating system it runs on: OS Yamato.

What is OS Yamato?

OS Yamato is a poetic, ephemerality-first operating system designed to let digital memories bloom and fade, like flowers in the wind.

Features include:

Diaries that bloom like seasonal flowers — and wither if forgotten

Photos and videos that quietly disappear unless viewed again

Chat with ambient seasonal effects and no pressure

A soft, nature-inspired calendar with reusable schedule templates

Wind Messages — time-delayed letters that arrive months later

A 3D globe to see fleeting connections blossom around the world

Each app within OS Yamato reflects a different way of embracing impermanence in the digital world.

Learn more about the concept and philosophy: [YouTube – Write a diary, and a flower will bloom](https://youtu.be/JrqwU_N5WBA?si=kZQAadNdBGipk6gz)

Try Hanaco Weather now: https://hanaco875.com

#ShowHN #HanacoWeather #OSYamato #solodev #minimalism #digitalpoetry #webapp #ephemeral

First of all, thank you I’m deeply grateful for the big response and the many new sign-ups to OS Yamato. The project was featured on Hacker News and briefly reached #23 on the trending list — a surprising and humbling moment for a solo developer.

GitHub stars, comments, and kind words have been flowing in from around the world. Thank you so much.

This project is still in its early stages, and I’m constantly learning and evolving it based on the feedback I receive. I’ll keep refining it slowly and calmly — in the same spirit OS Yamato aims to embody.

General reply to all (HN):

Thanks so much to everyone who’s checked out OS Yamato or Hanaco Weather so far!

I’d love to hear what you think after trying it out — what felt surprising, what worked well (or not), or just how it made you feel. Feedback, impressions, even short thoughts are all super welcome

The idea behind OS Yamato is to explore a calmer, more poetic way of interacting with data. If that resonates with you, I’d be thrilled to hear your experience.

→ https://hanaco875.com (sign up with just an email)

Thanks for checking it out! I’m always happy to answer any questions or feedback — feel free to comment anytime.

(Also open to ideas or collaborations — you can find me on GitHub or Twitter if that’s easier!)

— Tsuyoshi