In a battle against the corrupted, you were sadly separated from your team, forced to defend against them alone. Overwhelmed and losing hope, you used your gun, conserving energy by dodging their attacks.

Then, a massive beam lit up the area, followed by a explosion that wiped out the corrupted. When the light subsided, you faced a figure with a cannon in her hand, her right eye ablaze.

"I'm Black★Rock Shooter. I noticed you, a lone Commandant, surrounded by the Corrupted. Am I right?"