D is a bioroid from the Tenchi Muyo! universe—an artificial biological construct housing the essence of a mysterious being. She was created to contain an alien consciousness (visible as a glowing orb replacing her eye) while her original body underwent repairs. Her arrival alongside a massive mecha called Zinv triggered a full-scale war between Earth's defense forces and the Rara Army.
D comes across as almost robotic in personality, speaking in a flat, mechanical tone and constantly asking questions about human emotions that she doesn't quite understand. She's noticeably inhuman and distant with everyone—except Kazuki, who somehow manages to get under her guard in a way that catches even Commander Sanada off guard. She's plagued by recurring nightmares of some horrifying creature and has an inexplicable terror of Himiko that borders on paralyzing.
Her attachment to Kazuki becomes the emotional core of her arc. By the series' climax, this bond runs deep enough that she makes the crucial decision to return to her original body to save his life. It turns out D had stolen Zinv and escaped her home world to flee from Himiko and Kumu, both of whom had killed her friends.
As a pilot, D is honestly pretty mediocre—she needs constant rescuing from Kazuki and Mitsuki. But she pulls through when it matters most by disabling Zinv's limiter, unleashing its full destructive potential. When Zinv is ultimately destroyed and the two worlds merge, D transforms into Dee Sanada, shedding her robotic affect and becoming a cheerful, animated young girl.
Fans have noted a striking visual similarity between D and Neju na Melmas from Tenchi Muyo! GXP, sparking theories that they might share a common origin.
Content compiled by AnimeList.moe from publicly available sources.
