Tatsuya is a clone of Terumichi Madoka but was given birth to by his wife Azusa and is therefore considered a son of Terumichi and a sibling of Kiyoko. He is fourteen years old and can use the Dynamis. He is extremely attached to his sister, as she is the only family he really has, his mother having descended into madness or depression following Twin X.
Tatsuya Madoka is much more trusting of the Countess than his sister, and he is much more of an Orgo team player than Kiyoko. He assimilates with the Orga group very easily, but he sometimes has trouble following the Countess's orders.
Kiyoko is about seventeen, was born before the Twin X terrorist attack, so she doesn't have the ability to use the Dynamis. However, she played a very important role in the series. She acts as a surrogate mother to Tatsuya and has a hard time accepting the Countess's help because she feels like the countess is trying to take her brother away from her.
Kiyoko tried to leave the Countess two times. The first time she was caught and was punished by the Countess by being thrown into the Hotel's underground prison. The Countess let her go after she left a second time, but she had to her work to pay her debt to the Countess. She ends up living in a dank apartment in the only urban area in the world, and works as a hostess at a gentlemen's club, since the music store she originally worked at closed down. However, she doesn't let Tatsuya know that since she doesn't want him to worry about her.
Kiyoko Madoka also loves music, and is a gifted vocalist and pianist; she has a heightened sensitivity to sound. She can match any sound to its proper note, and was taught to play the piano by her father when she was very little.
All she wanted is a peaceful life with her brother, but her mother's debt and the conflict between the Gilgamesh and Orga keep haunting her, as well as the memory of what her Father did, so she can never find any peace.
She eventually falls in love with Novem, one of the Gilgamesh, which was reciprocated, and carried a child which would be the first of a short-lived new species.
There are a total of 10 Gilgamesh 4 women and 6 men. Their names are Uno, Duo, Octo, Sex, Novem, Tria, Quattore,Cinque, Septem, and Decem. Their names relate to their experiment numbers at Heaven's Gate before they were released by Enkidu on Twin X. There names meanings are as follows:
1. Uno: One
2. Duo: Two
3. Tria: Three
4. Quattore: Four
5. Cinque: Five
6. Sex: Six
7. Septem: Seven
8. Octo: Eight
9. Novem: Nine
10. Decem: Ten