Local vouchers that only work on the shopping street.
A chamber of commerce issues premium vouchers on Sui: pay ¥10,000, get ¥12,000 to spend at local shops. The shop is paid in the same transaction as the resident pays, staff add a stamp with one tap, and the city can check every yen. Try it from three sides:
Resident
Yuki's vouchers and stamp card. Pay a shop, collect a bonus.
Shop counter
See money arrive the moment Yuki pays. Give a stamp: +1, confirm.
City dashboard
Where the subsidy went, which shops need a visit, every event.
Everything runs on Sui testnet with demo accounts that this server signs for, so you don't need a wallet. Demo yen (dJPY) only; no real money.