From your very first wallet through to tax and security.
What crypto is and how it works. Read these in order to build a foundation.
Start hereBeginnerA crypto asset is a digital asset recorded on a blockchain — a public ledger that tracks balances and transfers without a central operator such as a bank. Prices are set by supply and demand and move a great deal.
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Start hereBeginnerBitcoin is the first crypto asset, live since 2009, with a protocol-level cap of 21 million coins. It was the first system to settle transfers without an operator.
5 min
Start hereBeginnerEthereum is a blockchain that runs programs — smart contracts — as well as payments. Most DeFi and NFT activity happens on it.
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Start hereBeginnerA blockchain groups transactions into blocks and chains them together. Altering an old record breaks every block after it, so tampering is detectable.
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Start hereBeginnerIn Japan, first confirm the operator is registered with the FSA. Then compare on three things: whether it lists what you want, whether you trade on a brokerage or an order book, and the fees.
7 min
Start hereBeginnerA wallet does not hold coins — it manages keys. Your assets live on the blockchain, and whoever holds the key can move them.
6 min
The words you meet on exchanges and in the news, one entry at a time.
Look up a termBeginnerA private key is the number that grants the power to move assets on a blockchain. Whoever holds it is treated as the owner, so the moment someone else learns it, the funds are theirs to take. Nearly all of crypto security comes down to protecting this one value.
5 min
Look up a termBeginnerA seed phrase is a list of 12 to 24 words that can regenerate every private key in a wallet. If your device breaks, the words rebuild the wallet. The flip side is that anyone who reads them owns your funds.
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Look up a termBeginnerA public key is computed from your private key and lets anyone verify your signatures. An address is a shorter encoding of that public key, and it is safe to share. Private key, public key and address are derived in that order, one way only.
4 min
Look up a termIntermediateA hash function turns input of any length into a fixed-length output. Change one character of the input and the output is completely different, which makes it a reliable way to detect tampering. That property is the foundation of a blockchain's integrity.
4 min
Look up a termBeginnerMining is the work of bundling transactions into a block and appending it to the ledger, rewarded with newly issued coins plus fees. Because participants spend real resources competing, rewriting the ledger becomes prohibitively expensive — which is what keeps the network secure.
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Look up a termIntermediateProof of Work grants the right to produce a block to whoever can prove they performed a large amount of computation. Rewriting the ledger would mean redoing all that work, which makes tampering economically irrational. It is the mechanism Bitcoin introduced.
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What each project is trying to solve. No price predictions here.
Understand an assetBeginnerXRP is the native asset of the XRP Ledger, a blockchain that has been running since 2012. It was designed to settle cross-border payments in seconds, and transactions are confirmed by validator agreement rather than mining. Ripple, a US company, has led its development and adoption, though the ledger itself runs independently of the company.
6 min
Understand an assetBeginnerSolana is a smart contract blockchain that launched in 2020. Parallel transaction processing gives it high throughput and low fees, and it hosts exchanges, NFTs and payment apps. It has also halted several times under load, particularly in its early years.
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Understand an assetBeginnerBNB was issued in 2017 by the crypto exchange Binance, originally as an ERC-20 token on Ethereum. It is now the native asset of BNB Chain, used both for fee discounts on the exchange and for gas on the chain. Its tight link to a single company sets it apart from other public-chain assets.
5 min
Understand an assetIntermediateCardano is a Proof of Stake blockchain that launched in 2017, notable for grounding its design in peer-reviewed research. Its native asset, ADA, is used for staking and fees. Because specifications are settled before implementation, features arrive more slowly than on many other chains.
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Understand an assetBeginnerDogecoin was released in 2013 as a joke about the crypto boom of the time. Technically it is a Litecoin derivative with Proof of Work payments. It has no defined use case or roadmap, and its price has been driven largely by celebrity posts and attention.
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Understand an assetIntermediateAvalanche is a Proof of Stake blockchain launched in 2020, built as three separate chains with different jobs. Ethereum applications run on its EVM-compatible C-Chain, and it lets companies and projects launch their own chains with custom rules.
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Opening an account, sending funds, setting up a wallet — step by step.
Learn the stepsBeginnerOpening an account at a Japanese exchange generally runs: register an email address, enter your personal details, submit identity documents, wait for review, then start trading. Most operators let you finish identity checks on a phone, and approval typically takes from the same day to a few business days. Before applying, confirm the operator is registered with the FSA as a crypto asset exchange service provider.
6 min
Learn the stepsBeginnerFunding a Japanese exchange with yen normally means either a bank transfer or a 'quick deposit' made through internet banking, which credits immediately. Whichever you use, the critical part is sending exactly to the destination and reference the exchange assigns to your account. Timing and who bears the fee differ by method, so read the operator's own guidance before you send.
5 min
Learn the stepsBeginnerMake your first purchase small enough that losing it would not affect your life, and pick a single asset whose mechanics you actually understand. Simply being aware of whether you are buying from the brokerage or on the order book already changes what it costs you. Work through it in three stages: decide the amount, choose the order type, then check what actually filled.
6 min
Learn the stepsBeginnerAn on-chain transfer, once confirmed, cannot be cancelled or reversed — there is no one to appeal to. Getting either the destination address or the network wrong usually means the funds are gone. That is precisely why you send a small test transfer first, confirm it arrives, and only then send the rest.
6 min
Learn the stepsBeginnerOn a brokerage the operator is your counterparty: it is simple to use, but the gap between its buy and sell quotes — the spread — is your real cost. On an order book you trade against other users, can place limit orders, and generally pay less. The same asset at the same operator costs a different total depending on which screen you use.
5 min
Learn the stepsBeginnerMetaMask is the most widely used self-custody wallet on EVM chains. Your keys live on your own device and the vendor never holds them — which means nobody can recover your funds if you lose the seed phrase, and they are gone the moment someone else has it. Only ever install it from the official site.
6 min
How to think about tax filing, and how not to lose what you hold.
Tax and safetyIntermediateTwo methods are used to work out the cost basis of a crypto asset: the total average method and the moving average method. The choice changes how gains fall across years, but over the full life of a holding the totals converge. Which method you may use, and whether a filing is required to elect it, is set by the rules — check the National Tax Agency's guidance and a tax professional.
7 min
Tax and safetyIntermediateA taxable event is not limited to converting back to yen: swapping one crypto asset for another, and paying for things with crypto, also realise a gain or loss. In Japan, income from crypto assets is in principle classified as miscellaneous income. Check the National Tax Agency's guidance and ask a tax professional how your own transactions are treated.
7 min
Tax and safetyIntermediateFiling for crypto follows three stages: gather your history, calculate the result, then enter it on the return. Whether you need to file at all, and where the figures go, are set by rules that change. Check the National Tax Agency's guidance, and engage a tax professional when the amounts are significant or the treatment is unclear.
8 min
Tax and safetyBeginnerSave your transaction history yourself, before it becomes unreachable. Exchanges limit how far back you can view, and a service that shuts down takes its records with it. How long records must be kept, and what counts as a record, are set by rules — check the National Tax Agency's guidance and a tax professional.
6 min
Tax and safetyAdvancedCrypto income is in principle miscellaneous income, and losses in that category cannot be offset freely against other kinds of income. What you can do with a loss depends on its classification and on rules that change. Check the National Tax Agency's guidance and consult a tax professional about your own case.
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Tax and safetyBeginnerPhishing works by showing you a convincing screen and letting you do the damage yourself. Never type a seed phrase or private key into anything. Reaching official sites only through your own bookmarks prevents most of it.
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