A song for a song. 95% of mine come from Japan.

Hi PH 👋 I'm m1chie, building solo from Japan.

Last March I shipped a tiny app called Song Bottle. It does one thing: you send one song you love, and a stranger somewhere sends one back. No login. No feed. No follower counts. A song for a song.

I assumed a few friends would play with it for two weeks and then forget. Instead the launch post got 90K likes, Japanese tech press picked it up, and the bottles kept flowing. iOS and Android followed.

Today, about 95% of users are in Japan. Which is wonderful — and also exactly why I'm here.

Why I built it

Spotify and Apple Music know my taste. That's the problem. After a while their recommendations started feeling like a mirror — "you liked X, here's more X." Comfortable, but airless.

What I missed was the texture of a human choosing a song for me. The mixtape from a college friend. A stranger on a train whose headphones leak just enough that I have to Shazam it. A song that has no business being on my "For You" page, but lands anyway.

There's a song I grew up with — Makihara Noriyuki's "The Night I'm In Now" — about thoughts traveling, on music, to someone you can't see. I wanted to turn that feeling into something anyone could do in 10 seconds.

What surprised me

I thought people would show up to receive — to discover new music. The bigger demand was the opposite: people wanted to send. To have one stranger, anywhere in the world, actually hear a song that mattered to them. Sending turned out to be just as emotional as receiving.

Why I'm posting on Product Hunt

Honestly? I want to break my own bubble.

The whole product is about escaping the algorithm and hearing what a stranger somewhere would pick for you. But right now almost every "stranger" inside the app is also Japanese. That's a beautiful pocket of taste — but it's still a pocket.

I want to know what someone in São Paulo would put in a bottle. What's playing in someone's headphones in Lagos right now. The song a developer in Berlin keeps going back to. The track a teenager in Mexico City wants one stranger to actually hear.

I'm hoping a few of you will throw a bottle in too — and that the next one I open sounds nothing like what my algorithm would predict.

We launch Tuesday at 12:01 AM PT. Hit Follow on this page if you want a ping when we go live.

And — what song would you put in a bottle right now? I'll drop mine in the first comment. 🍶