[4] The styling of the trains was overseen by Tanseisha, a company involved in designing commercial buildings along the Tokyu route.

[1] The classification "2020 series" for the trains was chosen to mark the year 2020 in which the Tokyo Olympics were scheduled to be held and in which Tokyu celebrated its 100th anniversary.

As of June 2023, the 3020 series lacks equipment needed in order to through run on the Sōtetsu Shin-Yokohama Line and associated through services.

Tokyu plans to install the required equipment to enable Sotetsu through service in the near future.

[17] Set 3121 had officially entered service along the Sotetsu network on September 26, 2023, over a half year later of the opening of the Sōtetsu-Tokyu Link Line.

They were originally built as such, but were initially operated as six-car sets, with two cars per set stored until 2022, when platform doors were extended to fit 8-car trains as part of Tokyu Corporation's strategy to cope with high demand on the Meguro Line and for the opening of the Sōtetsu Tōkyū Link Line.

[2][19] All three trainsets are distinguished with an “8-Cars” sticker located on the front window of the first and last cars, and are formed as follows: The original six-car formation was as follows:[20] The manufacturers and delivery dates for the fleet are as shown below.

On 10 April 2022, 3020 series set 3021 received a special livery to commemorate the 100th anniversary of Tokyu Corporation's founding.

[26] On 17 April 2023, 3020 series set 3022 received a colorful rainbow Sustainable Development Goals (SDGs) livery.