Income Tax

Calculates Japanese income tax (所得税) for self-employed individuals filing blue returns, walking through income computation, deductions, and tax amounts in sequence. Assumes you've already completed your settlement books and handles the full pipeline: imports withholding slips and payment statements via OCR with dual verification, registers dependents and spouse info for deductions, processes iDeCo and medical expenses, then computes the final tax liability with proper rounding rules (課税所得 to nearest 1,000 yen down, 復興特別所得税 to nearest yen down). Output feeds directly into the e-Tax filing system. This is built for the Japanese tax code specifically, complete with references to form fields like 第一表 and 第二表, so it won't help if you're filing elsewhere.