Iwai

Weekday departures: 3/day in the available timetable data · Sat & holiday departures: 3/day in the available timetable data

Earliest / latest departure in the available data (weekday): 15:21 / 17:12

Busiest hour in the available data: 15:00–16:00 (1)

0:00 ─ 23:00

Figures are typical departures in the timetable data, not a live service count.

Timetable data as of 2 May 2026.

The timetable data is incomplete for some or all lines at this station, so the weekday and Sat & holiday figures are departures in the available timetable data, not totals.

Lines where the timetable data is incomplete:

• JR Uchibo Line: only trains from timetables filed under other lines

• JR Uchibo Line: Hota (Chiba) ⇄ Tomiura (Chiba)

Iwai Station opened on 10 August 1918 on what is now the Uchibō Line, in present-day Minamibōsō, Chiba Prefecture. The station lies 73.7 kilometres from the western terminus of the line at Soga. It became part of JR East with the 1 April 1987 privatisation of the Japan National Railways. The station is an at-grade stop with a single island platform connected to the station building by a footbridge, and remains staffed. The surrounding area, formerly the seat of Tomiyama Town, retains the former Tomiyama Town Hall building.