{"country":"jp","currency":"JPY","name":"Japan","taxYear":2025,"taxYearPeriod":"January - December 2025","description":"Japan Self-Employed Tax Calculator (Income Tax, Resident Tax, Business Tax, NHI, National Pension)","parameters":{"income":{"type":"number","required":true,"description":"Annual gross business income JPY"},"incomePeriod":{"type":"string","default":"yearly","options":["monthly","yearly"]},"expenses":{"type":"number","default":0,"description":"Annual deductible business expenses JPY"},"blueReturn":{"type":"string","default":"full","options":["full","paper","basic","none"],"description":"Blue return deduction tier"},"businessTaxRate":{"type":"number","default":5,"options":[3,4,5],"description":"Business tax rate %"},"nhiRate":{"type":"number","default":10,"description":"NHI income-based rate % (varies by municipality)"},"consumptionTax":{"type":"boolean","default":false,"description":"Consumption tax registered (10%)"},"weeklyHours":{"type":"number","default":40,"description":"Weekly working hours"},"paidDaysOff":{"type":"number","default":15,"description":"Annual leave days"}},"example":"/v1/calculate/jp?income=5000000"}