Aqua Coin
Aqua Coin is the digital community currency of Kisarazu, Japan, launched in October 2018 by the Kimitsu Credit Union together with the city government and the local chamber of commerce. Residents charge yen into a smartphone app at a fixed one coin = one yen and pay by QR code at roughly 900 participating shops, keeping spending circulating inside the local economy. The currency doubles as civic infrastructure: a step-counting health program pays walking rewards in coins, payment chimes feature voices from local communities, and member shops donate 1% of their annual Aqua Coin revenue to school-meal projects sourcing local and organic food.
A quietly excellent Japanese credit-union community currency: seven-plus years of a perfect 1:1 peg, roughly 900 shops, and genuine civic wiring (health rewards, school-meal funding) — structurally still a custodial, yen-pegged municipal prepaid system with no sovereignty or fiat-independence dimension.
M69 Score
Scored against the Money2069 Manifesto — see methodology. Higher = more aligned.
Detailed Rating Breakdown
Issuance Model3x3.0
Single institutional issuer (IM-01: 1) but issuance is debt-free prepaid conversion of yen (IM-02: 4), supply is elastic with charges and spending (IM-04: 4), and balances carry validity periods so supply also contracts (IM-05: 4); backing is yen deposits only, no real-economy signal (IM-03: 2).
Spending Power Stability2x3.0
Fixed 1 coin = 1 yen held perfectly for over seven years of operation (SPS-04: 5) through a simple full-reserve mechanism (SPS-01: 3), but the benchmark is a single moderate-stability fiat (SPS-02: 2), reserve reporting is not public (SPS-03: 2), and usability is limited to one city (SPS-06: 1).
Fiat Independence & Interoperability2x1.0
A yen-denominated, yen-backed prepaid system dependent on banking infrastructure at every step; no fiat-independence dimension (FI-01/02/03/05: 1); closed single-app design with no composability or interoperability standard (FI-07/08: 1).
Traction2x3.0
Active with official news items dated within the last week (TR-01: 5); 7.5 years of continuous operation (TR-02: 4); roughly 900 member shops, up from 317 at launch (TR-04: 3); tens of thousands of app users in a city of 136,000 (TR-03: 3); strong local cultural identity with celebrity payment voices, a mascot, and citizen-proposed programs (TR-11: 4); pricing remains in yen (TR-05: 2) and campaigns lean on point-reward incentives (TR-09: 3).
Sovereignty1.0
Fully custodial operator-run system that the credit union or city could shut down unilaterally (SO-01: 1, SO-04: 1); proprietary app stack (SO-02: 1); operator has full transaction visibility (SO-08: 2); rules are policy, not code (SO-09: 1).
Governance2.0
Run by a formal three-institution partnership (city, credit union, chamber of commerce) with municipal accountability and public reporting (GO-01: 2, GO-03: 3), but no participant governance (GO-02: 2) and issuance rules changeable by the operators, constrained mainly by Japanese prepaid-payment law (GO-08: 3).
Resilience3.0
Survived COVID and 7+ years of operation, including delivering municipal support payments (RE-01: 3, RE-06: 3); simple, maintainable full-reserve design (RE-04: 4); institutional backing gives durable but budget-dependent funding (RE-07: 3); single vendor app is a real single point of failure (RE-02: 2).
Inclusivity3.0
Free to join with cash charging at ATMs and convenience stores, no bank account needed (IN-02: 4, IN-06: 3); benefits deliberately flow to community goods through the 1% school-meal program (IN-04: 4); equal rules for all users (IN-05: 4); but participation is geographically restricted to one municipality (IN-01: 2).