This is the 7285th most frequent Japanese word.
丸ノ内線
"Marunouchi Line" is a subway line in Tokyo, Japan.
Here, '丸ノ内線' is used as the subject referring to the specific subway line utilized for commuting.
私は丸ノ内線を使って通勤しています。
I commute using the Marunouchi Line.
In this sentence, '丸ノ内線' is being described geographically, noting its route through Tokyo's central areas.
丸ノ内線は東京の中心を通っています。
The Marunouchi Line runs through the center of Tokyo.
Here, '丸ノ内線' specifies the line of train that is arriving, indicating the timetable for this specific line.