(from ebookjapan):

Kaijo Tsuyoshi is the son of a Shorinji Kempo dojo owner. One day, he is ordered to wear a costume that was delivered to his father. He is told to put on the costume, which gives him superhuman strength, and fight with his friends, and his father is killed!

The enemy are the Black Crusaders, international merchants of death. A shadowy army of nations around the world has joined forces to form the EGL (Eagle) , the Kanto Branch of the EGL Japan Bloc works with Goranger to combat them!

What released by Seven Seas Entertainment as part of their Classics Collection lineup only contained a portion of the total four volume Goranger. What was brought was written and illustrated by Shotaro Ishinomori, and composed 1 1/2 volumes worth of content.

The remaining volumes contain Goranger serials written and illustrated by Ishinomori's assistants. The contents in them are highly suggestive, and comparable to the tone one would find in a Go Nagai manga.

Official English