One Small Message About What I Want to Learn — Building Haru Hana, Day 1
I’ve come across services that send a short piece of writing or something new to learn every day. I liked the idea: one small message, easy to fit into an ordinary day.
But the services I tried or looked at had fixed topics or a limited selection. I couldn’t always find something that matched what I actually wanted to explore.
That made me wonder:
What if I could choose my own topic and receive one message about it every day?
That’s where the idea for Haru Hana began.
What I’d like to receive
There are plenty of things I’d like to learn: useful English expressions, Japanese for travel, art history that helps me appreciate a painting, and small introductions to philosophical ideas.
But I don’t always want to commit to a course or a whole book. Sometimes I’m just curious and don’t know where to start.
A short daily message could be a welcoming first step:
An English expression, with an example of when to use it
A Japanese travel phrase, with a pronunciation guide
The historical context behind a work of art
A philosopher’s idea, paired with a question to think about
A small habit for taking better care of myself
One practical step toward starting a side project
I’d like to go beyond choosing from a few categories. Ideally, I could write something like, “I’m completely new to Japanese and want to learn useful phrases for a trip.”
The experience I’m aiming for is simple: finish reading and think, “Oh, I learned something new today.”
Starting with a seven-day prototype
This is my first attempt at building a service on my own, so I wanted to keep the starting point manageable.
I decided to build a working prototype within a week, see whether other people would want to use it, and document the process here.
On Day 1, I worked with Codex to build the initial flow:
A landing page introducing Haru Hana
A text field for entering a topic
Options for message length, preferred delivery time, and channel
A preview of three sample messages
A page explaining the current beta status
The app uses Next.js, TypeScript, and Tailwind. I’m learning about the tools along the way, but most of today’s decisions were about the experience: what someone would enter, and what they would expect to receive.
A calm place to return to
For the design, I chose a cream background with peach accents and muted green.
Since this is something people might open briefly every day, I wanted it to feel warm, simple, and comfortable to read.
There are two message-length options: a short, light read and a slightly deeper explanation.
An English expression and an art history story won’t necessarily need the same amount of space. I’d like to explore what feels useful without becoming a chore to read.
What the prototype actually does
Right now, the previews use prewritten text with the selected topic inserted. They don’t yet contain AI-generated lessons tailored to someone’s interests or level.
The app also doesn’t save input or send emails. Choosing a time doesn’t schedule a message, and opening the beta information doesn’t submit an application. These limitations are clearly stated in the interface.
KakaoTalk delivery is marked as “coming soon,” pending a review of business eligibility and messaging policies.
The app runs, its production build and TypeScript checks pass, and I’ve checked the browser flow from topic selection through message previews and beta information. Testing on a physical phone is still on the list.
What I learned today
“Send me a daily message about my chosen topic” sounds like a small idea, but it involves more decisions than I expected.
Travel Japanese and Japanese grammar are different needs. A quick introduction to philosophy and a question for deeper reflection are different experiences, too.
Eventually, the service will need to understand not just the topic, but also why someone wants to learn it and where they’re starting from.
Accuracy will matter as well. I’ll need to think about how to explain when a phrase is used, distinguish historical facts from interpretations, and provide useful references.
Next, I’d like to show the prototype to three to five people and ask:
What topic would you want to receive a daily message about?
Is there something you haven’t been able to find in existing services?
How much would you comfortably read each day?
What would make you want to open tomorrow’s message?
Haru Hana started with something I wanted for myself.
Now I’d like to find out whether other people have been wishing for something similar.