Tools

Every tool here is a single HTML page that runs entirely in your browser — no accounts, no backend, and nothing you enter leaves your device. The one exception is opt-in: AI-assisted features call Anthropic directly with your own API key, only when you use them. The flagship, Taigan Bridge, is meant to be downloaded and opened locally; the copy hosted here is a guided demo loaded with sample data.

Flagship

Taigan Bridge

Financial, tax, estate, and health planning for Americans on the opposite shore.

Sixteen bilingual EN/JP modules — net worth, FBAR, tax coordination, retirement projections, estate, property, family, healthcare, and more — behind a short branching onboarding so the dashboard only shows what applies to your household. Local-only: your data lives in your browser, no accounts, no telemetry. The copy hosted here is a guided demo pre-loaded with a sample household; download the single HTML file for real use.

Coming soon

FBAR Calculator

Track FinCEN 114 filings year by year, with Treasury rates built in.

Planned standalone version of Taigan Bridge’s FBAR module: a year-by-year filing tracker using official Treasury year-end exchange rates, multi-filer households, and passbook/statement import.

Coming soon

Furusato Nozei (US Persons)

Hometown tax, with the US-person angle accounted for.

Planned: donation-limit estimation that also surfaces the US-side questions a hometown-tax donation raises for US persons.

Coming soon

Nenkin Projection

Project your Japanese pension from your record.

Planned standalone version of Taigan Bridge’s pension tooling: 国民年金/厚生年金 vesting, gap years, and how a US Social Security record fits alongside. Reads your 年金定期便.

Coming soon

Payslip Decoder

Understand every line of a Japanese payslip.

Planned: paste or photograph a Japanese payslip and get every line — earnings, deductions, social insurance — explained in plain English.