Koenji is one of my favorite Tokyo neighborhoods: full of cool small businesses, great food, live music, Itoh Toyo’s new theatre ZaKoenji, and many places to explore. But the plaza in front of the Koenji station is unbelievable ugly and full of dead space.
Apart from the thinnest border of flowering azaleas and a few sparse trees, the space is mostly dedicated to cars and buses, with a large concrete plaza that is difficult to access. This enormous public space is impermeable to rainwater and unwelcoming for resting or socializing.
Given how walkable the neighborhood is and how many people arrive in Koenji by transit, it is a lost opportunity to create a great public space focused on residents and visitors. Redesigning this entry point to the neighborhood could be low cost and high impact.
Tokyo Green Space 
At least, they should plant more trees in the middle to create a small forest. I agree with you: it is sad to see this sight as soon as coming out from the station. Koenji is a great neighborhood. They can do better!
せめて真ん中の空虚にたくさん木を植えて、小さな森を作ればだいぶ違うと思うのですが。駅を出てすぐにこの風景を目にすると、悲しいですね。高円寺はすごく良い街なので、もっと変えられるはずです！
久家衆生さん、ありがとうございます。I agree with you, and appreciate your commenting in English and Japanese!