Hirokawa
Founded in 1843, this is the oldest eel restaurant in Kumagaya. A noren-wake (authorized branch) of the famous Hirokawa in Kyoto Arashiyama, preserving over 180 years of Edo-era tradition. Located 6-7 minutes on foot from Kumagaya Station in a classic wooden building. Eel rice bowl (upper) from 3,300 yen—a price point that keeps locals coming back in this hottest-city-in-Japan. Tabelog 3.50/126 reviews, Yahoo Maps 4.21. Private rooms for 4-30 guests. Reservations accepted.
Reviews praise 'Fluffy, large eel - a superb unaju', 'A genuine old establishment tracing back to the Edo era', 'Same flavor as the Kyoto Arashiyama Hirokawa'. TripAdvisor 4.4/5 (10 reviews), Yahoo Maps 4.21. Tabelog 3.50/126 includes many repeat-visitor comments: 'Come every summer', 'For eel in Kumagaya, this is the place'. Negative reviews only about limited seating and cash-only — no fake review suspicion.