I was in Tokyo recently for the 8th edition of Japan’s largest retail cosmetics trade show: Cosme Tokyo 2020 took place from 20th-22nd January at Makuhari Messe. The trade fair had relocated from Tokyo Big Sight exhibition centre to Makuhari in Chiba prefectures a few years ago – in 2021, however, Cosme Tokyo will return to Tokyo Big Sight.
Anyway, Makuhari Messe is around 40 minutes by local train from Tokyo Station – i.e. good transport connections if you’re staying in the Chiyoda area. I had booked my hotel in Kanda (one stop away from Tokyo Station) so my daily commute to the trade show was very manageable.