The Design Philosophy Behind Kazu-SRS and How to Use It

1. Just answer, and your learning moves forward

When you open Kazu-SRS, press the Start button. All you need to do is choose an answer from four options and move on to the next question. That is it. While you are studying, you do not need to open complicated settings or judge how well you understood the word yourself.

This is not just simplicity for its own sake. Kazu-SRS was designed with one goal: to maximize learning effectiveness. Let me explain the thinking behind it.

2. What settings and self-ratings take away from learning

If you have ever used an SRS app, you may have stopped at the initial settings screen.

How many new cards should you study per day? What should the learning steps be? Should you adjust the difficulty factor? What should the maximum number of reviews be?

While you are facing that settings screen, you have not learned even one word yet. Still, you are making decisions, and that steadily uses up energy.

And while that energy is being spent on settings, Kazu-SRS could already be moving you through several words. The difference between an app with settings screens and an app where you simply press Start accumulates with every session.

The time spent on the initial setup alone could be enough to answer about 100 quiz questions in Kazu-SRS.

Self-rating uses another kind of energy

In SRS systems where you rate your own answer with options like “Easy / Good / Hard / Again,” you have to judge your level of understanding after every question.

Each judgment may take only a few seconds. But if you go through 1,000 cards, that is 1,000 judgments.

In Kazu-SRS, the system automatically judges whether your answer is correct or incorrect. You do not need to do that work. The energy that would have gone into judging your own answer can go directly into remembering.

Use your resources only on what is hard to remember

Words you already know are better confirmed in real usage than by repeatedly checking that you still know them. Instead of spending resources on confirming what you already remember, it is more effective to spend those resources on words that are hard to remember.

3. The original Kazu-SRS algorithm

The spaced-repetition algorithm inside Kazu-SRS runs on an original 15-stage table.

This is not an abstract theory designed for an ideal learner. I have directly taught more than 1,000 learners in real classrooms and lessons. I have worked seriously with learners through major turning points in their lives, including school advancement and employment.

Through that work, I kept pursuing the best results with the best possible time efficiency. Kazu-SRS is one crystallized result of that experience.

Here are some of its original features.

Only missed words enter review

Not every word goes onto the review schedule. Only words you miss do.

If you start a 1,000-word deck and already know 300 of those words, those 300 words do not take your time. You can focus on the remaining 700.

Detailed reviews happen on the first day

Human forgetting moves quickly in the first few hours. The basic idea behind the forgetting curve described by Ebbinghaus in the late 19th century still matters today.

In Kazu-SRS, the moment you miss a word, that word comes back at short intervals: about 10 minutes, 30 minutes, 1 hour, 3 hours, 6 hours, 12 hours, and 24 hours. The system densely covers the time range where forgetting is most likely.

After that, as you remember the word, the intervals gradually grow: 2 days, 3 days, 5 days, and so on.

Review intervals extend up to 35 days

The intervals do not grow forever. The longest interval is 35 days. If you answer correctly at that final review stage, the word is removed from the review list.

Your relationship with Japanese will continue long after you finish a deck. For example, N5 vocabulary contains many extremely frequent words. Once you have learned them, you will meet them again in real usage. That is why Kazu-SRS does not keep chasing graduated words forever.

Repeating graduated words over and over is an extremely inefficient way to study.

Still, you may sometimes want to check whether a graduated word is truly safe. For that, Kazu-SRS includes Evidence mode, which prioritizes words with fewer total practice attempts. Practice mode also lets you go once through the entire deck, so you can use that as another way to check.

4. What each mode is for

Kazu-SRS has several modes. Each one has a different role.

Smart Start

This is the main starting point.

When you choose Smart Start, Kazu-SRS first clears the words that are waiting in Due review. Once those are finished, it automatically moves into full-deck Practice. You do not need to think, “What should I do today?” Open the app, press Start, and the questions appear in the optimal order.

By continuing with Smart Start, you can follow the highly efficient vocabulary-learning path that Kazu-SRS was designed to provide.

Practice

This mode takes you once through the entire deck. Each word appears once per cycle.

Use it when you want to review everything in order or keep broad contact with the whole deck. It is also the main mode for going through the full range before an exam.

Weak Point

This mode prioritizes words with lower accuracy.

You do not need to search for what you are weak at. Kazu-SRS judges from your learning history and automatically gathers weaker words for you. It gives you a concentrated experience of working on the words you struggle with.

Evidence

In a four-choice quiz, some answers will be correct by chance. There are also words that have appeared only a few times, so it is not yet clear whether you truly know them or simply guessed correctly.

Evidence prioritizes those words. Its role is to fill coverage gaps and confirm lucky correct answers with real correct answers.

SRS List

This mode lets you see which words are currently on the review schedule.

It helps you check, visually, what you are getting stuck on right now. There is also a “Remove SRS” button, but it is an emergency exit for when you truly want to stop reviewing a specific word. You do not need to touch it in normal use.

Fully Random

This mode gives questions in a purely random order. You can use it like a test.

It is not intended as the main way to study. Because the order is not optimized, it is less efficient than the other modes for learning.

5. When and how to use Kazu-SRS

There are two broad situations in Kazu-SRS.

The first is first-time learning, where you meet words you do not know yet. You read the example sentences, read the explanations, make mistakes, and gradually learn. Each question may take time. Please read the example sentences carefully. They also help you acquire grammar.

The second is review, where you check words you have already studied. If you remember the word, you can answer the four-choice question immediately, so each question becomes much faster.

Everyday study

Open Smart Start, press Start, and answer the questions that appear. That is all.

Five minutes a day is fine. Ten minutes is fine. One hour is fine. Answer the questions that appear, and when you are tired, close the app. That pace is enough. If you like setting a daily quota, you can. But Kazu-SRS was made so that you do not even need to spend attention on that. Just use it, and the time you spend will steadily turn into progress.

One week before an exam, when you do not know what to do

As an exam approaches, you may feel that you have to review everything, then end up unsure where to start.

At that point, just keep running Kazu-SRS.

Words you already know will move quickly. Words you miss will enter the review schedule and come back at short intervals. As you move through the full range, the system automatically picks up the words you had not actually remembered.

This is one of the best answers to what you should do before an exam.

The day before an exam

Try going once through the full range. Reviewing more than 1,000 words may sound enormous, but if you answer each question in 5 seconds, 1,000 words takes about 85 minutes. Of course, missed words will be brought back again, so in practice, 1,000 words may take around 3 hours.

The morning of the exam

When you open the app, the words you are weak on will appear.

You can do one final check in a short amount of time.

This is an extremely powerful exam-day strategy.

After the exam, six months later, one year later

After the exam is over, some time may pass, and one day you may wonder, “Do I still remember that word?”

When that day comes, open Kazu-SRS again.

If you can answer a word immediately in the four-choice quiz, it takes almost none of your time. Words you have forgotten are automatically picked up for review. As you keep going, you will naturally see how much of what you once studied still remains with you now.

6. It is a vocabulary app, but not only that

Each Kazu-SRS word card includes more than just the word itself.

• Furigana
• 5 example sentences
• English translations of the example sentences
• An explanation of the word

You may be answering because you want to remember the word. But while you read the 5 example sentences, you are also absorbing how that word combines with verbs, which particles it takes, and what kinds of contexts it appears in.

Consciously, you are only choosing the meaning of a word. But at the same time, unconsciously, you are also building grammar and reading comprehension.

The example sentences are written one by one by an active Japanese teacher with 12 years of teaching experience.

7. About Mark as Miss

So far, I have explained that Kazu-SRS is designed so that you do not have to judge yourself. But Kazu-SRS also gives you one way to add your own judgment and make the system even more accurate: the Mark as Miss button.

Because a four-choice quiz has four options, some answers will inevitably be correct by chance. There will be moments when you think, “I got it right, but I was not really sure,” or “I think I guessed.”

When that happens, press Mark as Miss. That word will enter the review schedule and come back later.

I strongly recommend using this feature actively. Each time you honestly mark an uncertain answer as missed, Kazu-SRS becomes more accurate for you. It is not required. But the more you use it, the more precise your learning becomes.

Study data and free access

Your learning record is saved inside your browser. If you delete site data or move to a different browser, your record may be lost.

Please use the Backup button regularly. You can restore saved data with the Restore button.

Kazu-SRS is free to use.

Open Kazu-SRS and answer your first question. A tool designed to make the best use of your time is waiting there.