Because FIEA Article 38-2 prohibits inducement bonuses to Japanese residents — including welcome bonuses, deposit matches, cashback, and most cash-prize PnL leaderboards. JFSA-licensed brokers can run virtual / paper-trading contests (which don't involve inducement to trade with money) but generally avoid live-money rank competitions for compliance reasons.

They operate in a grey zone. The JFSA issues 無登録海外業者 (unregistered offshore broker) warnings about platforms not holding JFSA registration. Japanese residents can technically use these brokers but receive no JFSA investor-protection coverage. Many Japanese traders use offshore brokers despite the warnings, but the legal status of contest winnings from those platforms is less clean than from JFSA-licensed venues.

Crypto gains are treated as miscellaneous income (雑所得) and taxed at progressive Japanese income-tax rates that can reach approximately 55% inclusive of resident tax, depending on total income bracket. Tournament prize income from trading platforms typically follows miscellaneous-income treatment. Professional traders may have business-income classification — consult a Japanese 税理士 (certified tax accountant) for amounts above modest thresholds.

Fintokei is a proprietary-trading firm that entered Japan in early 2023 and has grown rapidly since — Japan is now Fintokei's most active market. They offer evaluation challenges with funded accounts following the standard prop-firm model. Yes, Japanese residents can participate; the firm operates via offshore structures rather than as a JFSA-licensed broker.

Yes — the World Cup Trading Championships and the U.S. Investing Championship accept Japanese residents as international entrants. The audited-statement requirement and contest-year structure are the same regardless of residency; you'd file Japanese tax on any prize income according to the miscellaneous-income / business-income classification.