Jason Kobayashi
I’m Jason Kobayashi, a software engineer in Tokyo. I tend to stick with long-term goals: learning Japanese, learning to program, and now building Mastermind Japanese. AI made me realize I could finally take an old goal seriously: build the kind of language-learning system I always wished existed. So that is what I am doing.
How I Think
I’m pragmatic and step-by-step. I like to stay with something until I understand it well enough to move on. That is how I learned Japanese: I decided one day I was going to get good at it, and kept going.
Why I Built Mastermind Japanese
I learned Japanese the long way: TV, classes, physical flashcards, old-school electronic dictionaries, and a lot of repetition. I used one Sharp dictionary for years, mostly for the flashcard feature. Mastermind Japanese comes from that experience. It still uses flashcards, but not as a pile of random cards. The goal is mind-driven practice: understand what the learner knows, what is shaky, and what should come next.
Why It Matters
Japanese is hard. Not because the words are hard to memorize, but because of how it’s put together: the word order, the verb forms, the particles, even the way you can leave the subject out. You’re not swapping vocabulary, you’re learning to put thoughts together a different way. That’s the hard part, and honestly what I think makes it worthwhile.
What pulled me in at first was how different it felt: fresh, difficult, a little mysterious. Looking back, I think part of it was a kind of calm that comes from order. My high-school Japanese teacher was a big part of it too. She was genuinely in love with the language, and it rubbed off. Later, after I’d already been studying for a few years, a part-time job at a Japanese restaurant showed me the work ethic up close. I saw how much care went into doing things properly.
I try to build Mastermind with that same care, and to get you fluent without wasting your time. It’s not a culture course.
Feedback
If you're using Mastermind, you can send me feedback from the account menu in the upper right after you're logged in. Tell me what's broken or confusing, and I'll work on fixing it.