Free wifi will be introduced at all Toei subway Line by March 2020.
It’s available at one train of Asakusa Line from 5th February already.
It’s very nice.
But don’t expect too much!
Because the active system at the station is slow.
http://www.kotsu.metro.tokyo.jp/newsevent/news/subway/2016/sub_p_201601265632_h.html
