This involves several legs: 1. Shinkansen (bullet train) from Tokyo to Hakata (Fukuoka) (approx. 5 hours, JPY 15,000-25,000). 2. Camellia Line ferry from Hakata (Fukuoka) to Busan (approx. 6 hours, JPY 10,000-35,000). 3. KTX train from Busan to Seoul (approx. 2.5-3 hours, KRW 60,000-85,000). Prices and durations are estimates and subject to change by individual operators. Overnight ferries may offer cabin options.