Keikyu banks on rotating seats
https://www.railwaygazette.com/traction-and-rolling-stock/keikyu-banks-on-rotating-seats/58982.article
I guess one of the reasons why Keikyu decided to incorporate toilets is potential reduction of train frequency in the future. It's taken for granted that trains with low frequency are equipped with toilets. That's because passengers have to wait for the next train for a long time, if they get off at intermediate stations to go to toilets.
