We follow Fighter D as he infiltrates the Ranger organization and participate in their Ranger exam. For the final exam, the Cadets are tasked with retrieving a key from their Junior members. When they realized that only 5 keys (and thus only 5 cadets can pass), the cadets was reorganized into two teams who fight over the keys. At the climax of the exams, each cadet engage in a showdown against their counterpart cadet in the same battalion for the key.