Inside JR Keiyo Line TrainJR京葉線車内EP 100:562026-01-17According to the original work, the group's return route roughly goes like this: from Maihama take the Keiyo Line to Chiba, Yukino and Dango get off at Kaihin-Makuhari Station, while the Oshi-sensei and Isshiki ride on to Chiba Minato Station and transfer to the monorail toward Chiba Station. So this segment should be between Maihama and Kaihin-Makuhari, but since the background has no distinctive features, it doesn't really matter.
Source:AnitabiReport an issue