Overview
- JR East announced on Tuesday that the new service will be called
- 'Luna Azul' and is slated to begin in spring of fiscal 2027.
- The service will switch by season, running as an overnight Shinagawa–Aomori route in spring through autumn with two roundtrips per week and as a daytime Shinagawa–Naganohara‑Kusatsuguchi shuttle in winter with six roundtrips per week.
- One existing 10‑car E657 series set will be rebuilt into an all‑Green‑car formation of 1–4 person private rooms, with larger 'premium' cabins at cars 1 and 10 plus an onboard lounge.
- JR East expects the overnight Shinagawa–Aomori trip to take about 12½–15 hours with capacity near 125 people and the winter daytime runs to take about 2½–3 hours with capacity near 150 people.
- Fares are expected to sit above Tohoku Shinkansen Green‑car levels but remain tentative, and the project reflects a wider push by Japanese rail operators to revive experiential overnight travel while reusing existing rolling stock to control cost and speed deployment.