Achika Masaki

Achika is Tenchi's mother and the daughter of Yosho (known on Earth as Katsuhito).  Achika died at a young age when Tenchi was still a young boy.  KAIN, a very powerful being that hates the power of Jurai, traveled back into time after escaping from the Galaxy Police Headquarters in an attempt to halt the Jurai family line.  Achika was his target and Tenchi and his group had to go back in time to help Achika to defeat KAIN.

The battle with KAIN awakened the latent Juraian energies inside her.  Her confrontation with KAIN drained Lady Achika severely and more than likely caused her early death.