There are ROM hacks for every NES and game that replace Mega Man with a female character.
Here is a tutorial on how to apply the ROM hack patches
Mega Man 1
Roll-Chanhttps://www.romhacking.net/hacks/1704
This is a player sprite hack of Rockman/Mega Man for the NES.
This hack changes Rock's player sprites into his sister Roll.
Created by Zynk Oxhyde.



Megagirl
https://www.zophar.net/hacks/nes/megaman/megagirl.html
This hack almost alters every in-stage enemy to look like a female.
Mega Man himself has been changed in that (s)he now has hips and a ponytail in every animation frame.
Created by blueboy aka bluexgreen
Can't find a copy of this anywhere. Please edit this if you have any information.
Megagirl V1.0 by Clomax Dominion (Megaman Hack)
This ROM hack changes the character in a subtle way, shirking the waist a little, and adding a ponytail.
The hack also changes some of the in game text as seen in the boss selection screenshot.


Mega Man 2
Megagirl 2In the sequel to Mega Girl, the protagonist with the ponytail must stop the eight Robot Masters that Dr. Wily created.
Unlike the first Mega Girl, most of the characters in this hack retained their original names.
Created by 'Mr. Dude' back in July 2005, but updated in August 2010.
Can't find a copy of this one either. Please edit this if you have any information.
Roll-chan 2
https://www.romhacking.net/hacks/2265/
Its time for Roll to spring into action once again.
Rock, her brother-in-arms, stays behind to assist Dr. Light in developing new weapons & items for Roll.
Created by Zynk Oxhyde.




These screenshots below are from the Mega Man 8 style.


Mega Man 3
Megagirl 3Created by 'Mr. Dude'
Roll-chan 3
https://www.romhacking.net/hacks/2266/
On her third adventure, Roll now has a support unit, Tango, her pet cat modified for combat, who can transform into transportation units.
Created by Zynk Oxhyde.



Mega Man 4
Megagirl 4Created by 'Mr. Dude'
Roll-chan 4
https://www.romhacking.net/hacks/2267/
With this new challenge, Roll doesn't fall short against new powerful enemies as she is equipped with a new weapon - the New Roll Buster, a powerful charged shot.
Created by Zynk Oxhyde.


Mega Francesca
https://www.romhacking.net/hacks/2196/
Replaces Mega Man with Francesca the Little Witch / Doropie from Vic Tokai's The Krion Conquest/Magical Kids Doropie.
Created by Korxtendo



Mega Man 5
Megagirl 5
Created by 'Mr. Dude'
Roll-chan 5
https://www.romhacking.net/hacks/2691/
To reach Protoman, Rock, has given his combatant sister Roll, his buster powerup, making her charged Roll Buster more power & range; despite him being benched for this act.
Created by Zynk Oxhyde.
Mega Man 6
Megagirl 6
Created by 'Mr. Dude'
Roll-chan 6
https://www.romhacking.net/hacks/2692/
With Mr.X revealing himself as a new despot controlling 8 powerful battle-type Robot Masters, Roll-chan is once again needed to save the world.
Created by Zynk Oxhyde.
Mega Man: Dr. Wily's Revenge
https://www.romhacking.net/hacks/3393/
This is a player sprite hack of Rockman World/Mega Man: Dr. Wily's Revenge for the GB.
This hack changes Rock's player sprites into his sister Roll.
Created by Zynk Oxhyde.