Yakage

Through information and seeing that this is based on the OVA since, Yakage had to be working as an apprentice of Washu 5,000 years ago because Kagato held her prisoner for the time after. Since Yakage was good at using swords his research topic was to produce the Greatest sword. And for the record, Ryoko's sword was created using the data in Yakage's thesis. (it never said that he wasn't pleased with the final product because I bet he knew it was the perfect sword.) It is not for certain how Minagi was created as the exact double of Ryoko but Washu Hypothesis that Yakage took some of Ryoko's DNA when they were in the early stages. (Which means that either Washu is the mother of two or Ryoko's a mother, whichever way you want to intermit it.) With this he added some of his own genes to Minagi. And just for the record your third paragraph is almost all wrong. Washu never condemned Yakage's work. Plus those aren't scars on Minagi checks. It's a way to tell a difference between them because Minagi is an exact copy of Ryoko.

There are multiple reasons why they aren't scars. One, scar are not passed on the genetic level. Two, the scar on Yakage's face is a memento to the first time that Minagi beat him. Three, if those were scars they would had been skin grafted over them, Minagi mentioned this in Sword Play page 71. Forth, they are way to sementrical to be scars. Fifth, they would be more distorted like Yakage's scar. Sixth, and probably the biggest reasons for the markings on her cheeks, if they weren't their weren't there, who would you tell the difference between them? But the last two sentence are pretty much right.

After her birth she trained her first. Then he sent her out to see if the news of Kagato's death was true. After that confrontation with Ryoko, Minagi develops amnesia. After befriending Sasami, Minagi leaves after Ryoko tries to smash Minagi with her 100 lb er. "Special Memory-Recovery Hammer" Minagi is then picked up by her ship's main unit, Hinase. Yakage later shows up after seeing the defeat of Minagi and discovers that Tenchi really does hold the "Lighting Eagle Sword" After a quick bout with his Guardians, Kuze and Hakkou, Yakage sees that Tenchi is not yet fully able to control the Sword and discovers that Ayeka she was the Jurai Princess who went off 700 years ago to find her bother.

He takes this opportunity and takes Ayeka hostage as a help to Tenchi's "attention deficit problem" and tells him he has 10 days to train before he would meet them again. After an unsuccessful attempt to rescue Ayeka is done by Ryoko, Tenchi and the other girls except for Sasami, all head off in Ryo-ohki to Yakage's ship. Minagi who now is on her masters ship fight's with him to get her memory back. Ryoko shows up and fight with Yakage only to be captured in the same type of force globe Ayeka is in. Tenchi then after destroying Yakage's guardians, finds Yakage fighting with Minagi who then gets sliced after recovering her memories and dies. Yakage though morns the death of his daughter, wants to fight with Tenchi to see if his Artificial Lighting Eagle Sword or the original is the best in the Universe. When Tenchi refuses to fight on Ryoko's pled, Yakage makes the Force Fields around Ryoko and Ayeka In the fight Yakage shows the true potential of with sword showing its defensive capabilities, knocking Tenchi unconscious. As Yakage is about to throw the death blow, Ryoko breaks free of the force field and saves the still unconscious Tenchi at the expense of herself. Ryoko who is know trying to get wake Tenchi up as Yakage moves in closer for the kill. Then after Ryoko cries a tear for him Tenchi transforms into that (Oh heck, I looked everywhere for what the power imbued by Tsunami is called.) But with that Yakage figures that, that is the real sword and shows Tenchi that his Artificial Lighting Eagle Sword is double bladed. (And for Gods sake, don't compare it with Star Wars.) After a massive passing and swinging of swords by the two combatants. Tenchi escapes unshaved while Yakage was sliced through from his shoulder, to his hip. While he disintegrates he tells Tenchi that he tried his best in coping the Lighting Eagle Sword but it would never be able to defeat the original. And though he failed, he did his best as a scientist and a warrior, and their was no dishonor in that. His only regret was for Minagi, he wanted his daughter to possess the perfect sword, and then dies.
As Tenchi comes to gripes with what he has done Washu and Mihoshi come into the room of the where the battle took place. Mihoshi then er. tends to Ryoko's injuries while Washu told Tenchi that Yakage died on his own wishes, and then reviled that again that Minagi was Yakage's daughter. Ryo-ohki then shows Mihoshi that Minagi is still alive but in a state of suspended animation and Yakage's sword didn't kill her and he programmed it so that her wounds wouldn't worsen. Ayeka is rescued and they all head back to Earth.

Three months later Mihoshi ran into Minagi in space and told to give them a message. It said that she was said at first about Yakage's death but she later felt better later. She decided to follow in Ryoko's footsteps and became a space pirate. Of course she would only rob from the bad people and bad cargo. It then shows that Mihoshi crashed into Tenchi's house (again). On a side note Minagi comes back in Volume four of the OVA Book series Samurai Space Opera. And Minagi also has a flash back when she was in a healing tank after a practice with her Master Yakage. When Hishima stole the Hielzen S Shadow Blade from Yakage after he threatened Minagi life in Volume five of the OVA Book series Unreal Genius.