Following the Tokyu-Setagaya line, I'm going to show you the other "SDGs Train" on the Tokyu-Toyoko line.
Let me quickly review the concept of SDGs Trains. The Sustainable Development Goals (SDGs) were adopted by all United Nations Member States in 2015 as a universal call to action to end poverty, protect the planet and ensure that all people enjoy peace and prosperity by 2030. Following SDGs, many companies, such as Tokyu Electric Railway, announced new initiatives taking into consideration, for example, environmental problems. Tokyu launched the special poster trains named "SDGs Trains" on the Setagaya, Den-en-toshi and Toyoko lines from September, 2020. The purpose of SDGs Trains is to provide a beautiful living environment. These trains are substantially powered by 100% renewable energy.
The SDGs train on the Toyoko line is set 5121 of the EMU Tokyu 5000 series. Set 5121 was built by Tokyu Sharyo in 2009. It was once launched on the Den-en-toshi line as a 10-car train, but moved to the Toyoko line as an 8-car train only one year after its debut. The reason for moving from the Den-en-toshi to Toyoko line was not clear, but probably because Tokyu held down the introduction of new rollingstock due to the harsh business conditions... namely Lehman's collapse. Tokyu's aggressive property investments had backfired at that time. Shortage of the trains on the Toyoko line must have been a serious problem.
Set 5121 had saved the Toyoko line, and become Tokyu's star... SDGs poster train.