"Hello, my name is Fish, and I am pregnant with Miku's baby."
-Luka introducing herself in Teto Does 9/11.Megurine Luka is a minor character that first appeared in Teto Does 9/11. She is the mother of Defoko, who was born one episode later.
Megurine Luka was born in Korea, the first introduced character to be born outside of Japan. Born with long, pink hair and blue eyes, not much is known about her.
When telling Miku about her impending pregnancy, Miku did not believe her, asking her to repeat herself. Luka then just said that she did 9/11, Teto coming out and proving her wrong. Nobody believed Teto.
Luka tried once more to tell Miku about her pregnancy, but Miku was in another conversation, so she probably didn't care much.
Luka was the one to tell Oliver about Gumi being born for the second time after Len gave birth.
It is possible that Luka and Miku were in a relationship, since Luka was pregnant with Miku's child. Luka gave birth to Defoko in Teto Does Pearl Harbor, and reunited with an old friend, Kagamine Rin. The two apparently did weed together in the past. The two also made out after Rin was crying. It is unknown if any relationship came out of this.