Tenchi Muyo! Daughter of Darkness (天地無用!真夏のイブ Tenchi Muyo! Manatsu no Eve), is the second of three movies set in the Tenchi Muyo multi-verse.
Unlike the first and third films - which carry on the story told in Tenchi Universe - it is an adaptation of the tenth novel by one of the original OVA scriptwriters, Naoko Hasegawa, set in its own continuity taking place after the first OVA and ignoring the subsequent sequels.
Seven hundred years before, a young Prince Yosho had met a young girl before the annual Startica celebration on Jurai. However, it turned out that the girl was actually a demon named Yuzuha and was driven away by the palace guards.
Seven hundred years later, Yuzuha discovers that Yosho was now on Earth... and has a grandson - Tenchi Masaki - who is surrounded by all sorts of women. Looking for revenge, the demon obtains hair from Tenchi and combines it with hair from herself and creates a girl named Mayuka.
From
Wikipedia