Build a Lasting Habit
Just 3 seconds a day. Simply choose "Good day," "Okay," or "Bad day."
No wondering what to write. Zero guilt for skipped days.
First, build the habit of recording itself.

Just pick from 3 choices daily.
AI finds your happiness patterns.

The "calendar circle-cross method" I described in my book 'The Mechanism of Happiness' has evolved. I sincerely hope that this app, developed by Saeki ā my former student and happiness researcher ā will help improve the well-being of many people.
Keeping a diary and reflecting on daily life is an effective practice for cultivating psychological richness. Translating psychological knowledge into everyday tools is a challenging endeavor, but Saeki's app shows real promise. I look forward to it enriching many people's lives.
Here's how your daily life will transform with this app
Your growth journey with 3-Choice Diary
First, form the habit. 3 seconds, 3 choices - no giving up.
Discover your values, strengths, and personality. "So this is who I am."
See trends in your "good days" and "bad days." AI provides hints.
Know the conditions for good days and incorporate them into your life.
Here's how 3-Choice Diary transforms your daily life
Just 3 seconds a day. Simply choose "Good day," "Okay," or "Bad day."
No wondering what to write. Zero guilt for skipped days.
First, build the habit of recording itself.

From continuous records, AI analyzes your values, strengths, and personality.
Schwartz Theory, VIA Character Strengths, Big Five.
Gain deep self-understanding based on psychological research.

Daily reports help you reflect on your emotions and their context.
"Why was today a good day?" "What made it just okay?"
A journaling experience with insights, not just writing.

As records accumulate, your unique "good day patterns" emerge.
What days bring satisfaction? What tends to lower your mood?
Let's discover tips for more good days together.

⢠You can just pick from 3 choices, or write freely - you can use it however you feel that day, so even I, who gets bored easily, can keep using it! ⢠The review reports come weekly, monthly, plus special reports. Recently I received a Self-Care Report and was amazed by its content. It was a week when something sad happened that I didn't want to talk about with anyone, but the report addressed it with such heartfelt content. ⢠I sent a request through the app to make reports printable, and soon after, a PDF export update was added!
I think even easily-bored people can keep using this diary. When sleepy or unmotivated, you can just pick your mood from 3 choices - that's great. Personally, my favorite point is the carefully crafted UI. No ads, user-friendly, and I really love the calm atmosphere.
The app gives faithful and accurate comments based on what I wrote, which makes me want to continue. Plus, the comments are gentle with no harsh advice, making it easy to open up completely.
Answers to your questions

Ph.D. A researcher in psychology and behavioral science, engaged in research on happiness and cognition. With a mission to "turn academic insights into tools everyone can use daily," he developed the 3-Choice Diary app. Supporting your mental care with research-based logic.
Record in 3 seconds, AI analyzes.
Find your "good day" patterns and
make every day happier.