Following our sessions at BGIN Block 14 in Tokyo, we have prepared the draft session report for: Practical Stablecoin Implementation Guide.
Review Request: Please review the attached draft for technical accuracy and provide any feedback, corrections, or additions directly in this thread by March 27.
Dear all, I have created my own summary of the second Agenda Item that was discussed within this Session i.e. the Agentic Payments workshop component. My summary provides some additional detail on that topic, to complement the overall session summary provided by Rola above. Please see the document attached, if of interest. Many thanks, Chloe.
It is a summary by another local LLM for the first part of discussion.
Practical Stablecoin Session — Pilot Discussion and Digital Garage POC (Challenges)
Context. BGIN Block 14, FASE: Practical Stablecoin Implementation Guide (Day 2, Room B). This note summarizes material from the meeting transcript through the Digital Garage / Myna Wallet retail-payment segment: the USDC registration-fee pilot, SBI VC Trade, floor discussion, and DG’s café POC (before the chair’s later AI agents × stablecoin exercise).
1. Purpose of the pilot (BGIN / Prof. Matsuo)
Block 14 was the first trial of accepting USDC for registration and sponsorship fees—not only discussing stablecoins but using them in conference operations.
The explicit goal was to surface friction across technology, operations, and regulation and to feed a structured list of difficulties into future improvements.
In Japan, SBI VC Trade was described as the only licensed path for the needed USDC ↔ JPY leg for yen-denominated treasury needs, which drove the partnership.
2. Regulatory and business constraints in Japan
Approx. ¥1 million equivalent cap on certain foreign-stablecoin flows (illustrated on the order of ~6,400 USDC in the discussion): limits on sending/buying/selling above that threshold in the regulated exchange / wallet context.
Large corporate-style limits were described as tight in practice (e.g., a ¥100 million per transaction framing was called out as constraining).
A custody-duration / balance rule for foreign stablecoins (USDC) on the exchange—cannot retain above a yen-equivalent threshold beyond six months—was said to push balances off custodial platforms into non-custodial arrangements, which is operationally burdensome for firms.
AML/CFT: enabling payments requires knowing provenance (where funds come from and from whom). That is hard to square with unknown counterparties and retail-scale payment growth.
JPY-denominated stablecoin issuance (SBI group context) was contrasted with foreign stablecoins still subject to the above constraints—cross-border payers who need yen conversion remain under the stricter foreign-stablecoin regime, limiting viable use cases.
An informal poll suggested only one participant had paid registration in USDC, underscoring adoption and liquidity as practical issues, not only rules.
3. Operations and KYC friction
Account opening at SBI VC for the Japanese non-profit supporting BGIN: the representative’s U.S. non-resident status added weeks of KYC/email back-and-forth; over one month to open the account.
Coinbase Commerce collected name, email, and physical address but lacked a field for purpose of transaction, which may be expected for cross-border payments—flagged as a merchant-rail / product gap to improve.
“USDC” vs. multi-chain reality: the same ticker on Ethereum, Base, etc. behaves like different settlement environments. Because SBI VC accepted only USDC on Ethereum for this flow, a payment on another chain could not be processed through the intended USDC → JPY path. A knowledgeable participant still mis-routed funds; the group stressed end-user confusion at scale.
Obtaining USDC in the U.S. (personal experience cited): credit-card purchase not available; bank transfer heavy under AML/KYC; instant acquisition only via a PayPal → linked bank (ACH) workaround—described as too difficult for average users, despite policy enthusiasm for stablecoins in both the U.S. and Japan.
4. Payment UX and routing
Coinbase Commerce was said to default to the cheapest-fee network (e.g., Polygon), so payers sometimes did not choose a chain yet settled on the wrong chain relative to the organizer’s requirement.
Merchants then bear responsibility to swap or bridge to the chain they actually need—operational overhead on the receiver side.
5. Cost
Participants briefly compared all-in cost and who pays fees (payer vs. merchant) and wrong-chain remediation costs; the chair then steered back to the published agenda (Digital Garage slot).
6. Digital Garage and Myna Wallet — retail stablecoin payment POC
Speakers (as in transcript).Shunichi Kimura (Head of Web3, Digital Garage) outlined the pilot; Shindo (CPO, Myna Wallet) followed with product detail and other POCs, in Japanese with consecutive interpretation.
6.1 DG context and pilot setup
DG described itself as a payment service provider (stablecoins as a near-term operational theme), Crypto Garage, and enterprise crypto custody (e.g. digital-asset treasury clients), with a goal to support Japanese enterprises on stablecoins over time.
Motivation: DG cited 1M+ merchants on its rails as a potential spend path for stablecoin holders; the pilot was framed as building real usage despite limited domestic holding today.
Venue / flow: Stablecoin payments at Pangea Café (10th floor of the Block 14 venue tower), with Myna Wallet support on technology and regulatory framing. JCB and Resona Holdings (large card network and banking group—ASR: “Risen”) participated to explore future integration.
Volume (stated):100+ transactions, split about half JPYC / half USDC. DG noted surprising USDC use, attributing it partly to inbound visitors to the Parco complex stopping at the café.
6.2 Technical pattern (high level)
Myna Pay:QR-based checkout, gas-sponsored transactions, and a regulatory framework for the POC. Wallets mentioned included a KYC-oriented Myna flow, Base App, and others via WalletConnect. Merchant experience: scan / confirm and deliver goods (e.g. coffee).
6.3 DG’s summarized challenges
Merchants: Adding the rail was described as straightforward; no negative store feedback in the POC.
Users vs. traditional payments: Even wallet-experienced users sometimes faced multiple authentication steps—more friction than cards or QR bank pay.
Privacy:Public on-chain history exposes who paid; merchant revenue can be inferred (Kimura cited one-time addresses as a parallel to patterns Stripe uses). Open need for mitigations at scale.
Compliance: Large players could restrict to KYC’d wallets, but non-KYC wallets (e.g. Base App) remain in the wild—tension over how strongly to push KYC and whether near–real-time KYT / API-style screening can avoid screening every small merchant payment without slowing checkout (DG runs a Japanese exchange and flagged this speed vs. control trade-off).
Licensing (scale-up):Who holds the license (e.g. JCB vs. DG) was described as under discussion.
Wallet architecture:Direct deposit to a licensed exchange is awkward for high-frequency small tickets because exchanges may need to screen each receipt—suggestion of self-custody / hybrid / proxy designs to combine exchange and payment needs.
Gas / economics: Gas in the POC ranged about tens of bps to several percent depending on amount, chain, and timing; for a payment operator gas is pure cost, and all-in pricing for future KYC / FX services was described as still unclear.
6.4 Myna Wallet — additional POC color and UX hurdles
Product:My Number card / JPKI-oriented non-custodial wallet with KYC (operator certification narrative as in transcript).
Other experiments: e.g. Fukuoka pro-basketball event with JPYC and physical My Number card tap-style flow; ongoing tests with JPYC and USDC.
Café QR POC:Myna Pay—customer scans merchant QR; pay from Base App, MetaMask, or Myna Wallet.
User pain points:On-ramping, understanding networks, mistakes (e.g. POC accepted JPYC on Polygon and USDC on Base, but some users sent JPYC on Avalanche); difficulty obtaining native tokens for gas even when the café flow was gas-sponsored (because acquisition paths still hit gas). Simpler UX may require legal clearance workstreams.
Scale vs. rules: Roughly tens of thousands of yen in sales over five days was mentioned alongside JPYC ~¥1M-type limits as a modeling / compliance constraint for something economically meaningful.
Privacy / policy hope (paraphrased): desire for frameworks where KYC’d wallets improve compliance and smooth use without abandoning payment privacy entirely.
6.5 Live anecdote
Same-day live payment demo at the café (~USD 250 equivalent cited): Base wallet payment failed (wallet tied to an unexpected address); USDC moved to MetaMask and paid via QR → merchant page → wallet choice → multiple confirms. Framed as illustrating shared UX pain with the POC team’s findings.