Bitcoin is the native asset of a decentralized blockchain network with a supply limit of about 21 million BTC. BTC/JPY quotes one Bitcoin in yen, so its yen value also responds to exchange-rate changes.
History and development
Bitcoin began operating in 2009 from Satoshi Nakamoto’s proposal for peer-to-peer electronic cash. Instead of entrusting a ledger to a bank or other intermediary, participants verify and share transaction records. Payments and ownership became possible on a network without a central administrator.
Trading markets and an open development community subsequently expanded worldwide. A capped supply and declining issuance became defining features, while protocol changes depend on proposals and adoption by participants. USD and JPY charts value the same BTC in different currencies; they do not represent separate crypto assets.
References: Bitcoin: origins and development
Comparing charts on this board
Pair BTC/JPY with BTC/USD and USD/JPY to separate the asset move from yen translation. Approximately, their product gives the yen value: BTC strength and yen weakness reinforce; yen appreciation offsets.
ETH/JPY adds an asset comparison sharing the yen layer. On weekends, separate crypto movement from regular FX, which resumes later.
Related charts: BTC / USD · USD / JPY · ETH / JPY
Official references: Bitcoin: how it works