Rockman Complete Works: Rockman 5 - Blues no Wana!?

About two months after Dr. Wily's defeat in Mega Man 4, Proto Man — once an uncertain ally — appears to have turned against the world, leading a robot army in destructive attacks and kidnapping Dr. Light. Mega Man sets out to stop him, supported by Beat (a bird robot from Dr. Cossack) and Dr. Cossack providing tactical backup. Eight Robot Masters fall — Star Man, Gravity Man, Gyro Man, Stone Man, Crystal Man, Charge Man, Napalm Man, and Wave Man — before Mega Man enters Proto Man's fortress. Inside, a second Proto Man reveals that the first is Dark Man 4, a robot built by Wily to frame his brother. Wily had done it to retaliate for Proto Man's interference in Mega Man 4's events. Mega Man pursues Wily, saves Dr. Light, and escapes the collapsing fortress. The real Proto Man, who blasted the exit, quietly slips away.