Washu
Pink, crazy, and with a hunger for learning, Washu adds both character, spunk, and plot to the series. Also trouble for Tenchi and the gang. In fact, nothing would really have happened at all, had Washu not come and caused some meyhem!
Though she looks like a twelve-year old, this little genius is actually over 20,000 years old! She created Ryoko in her lab, can predict almost every move the enemy can make, and made extra space inside of a cramped broom closet for her ever-growing lab by expanding the atoms of the house. Don't get it? Just nodd and smile like you understand, it works for Mihoshi.
Washu, being Ryoko's mother, can connect telepathetically with the demon. But she doesn't really pay close attention to who steals DNA from her experiements, because there are Ryoko coppies running around that weren't made by Washu. Though they are related, that doesn't mean they get along---and they don't. In fact, other than Ayeka, Washu is the one person Ryoko can get really mad at. And I won't say that Washu doesn't deserve it 99.9% of the time...
Before Washu was locked away in the reverse world of Kagato's space ship, she had a husband--and a child. But they were both taken away from her when her research got too critical. The government whipped up some papers and Washu was on her own once more. Deciding that she never wanted to grow up or fall in love again, Washu fiddled around with some gadgets, pulled some levers, and "Poof"! her body doesn't age any longer! Nifty, isn't it?
Washu doubles as a scientist and a loving parent. Though Ryoko doesn't willingly show affection often, Washu really does care. In fact, she usually tags along for the fights to make sure she's there if ever needed. When Tenchi's relatives dropped their baby off at the Masaki residence for a stay, Washu learns to love the baby...just like the one she had before. "No, baby...I'm not your Mommy..." When the baby has to go home, Washu gives more attention to Ryoko, hoping that she can make a fresh start with her beautiful daughter.
Washu only shows a vauge romantic interest in Tenchi. Sure, she'll flirt a bit, but she's more interested in learning about what makes him tick than what turns him on. I'll let you decide if she's crazy, or just out-of-the-ordinary...