Hosokawa Gracia was named Tama at birth. She was the daughter of Akechi Mitsuhide, one of Oda Nobunaga's vassal who also betrayed and killed him later. She was wed to the Hosokawa family, by Nobunaga's recommendation. She led a peaceful life until Akechi Mitsuhide plot a treasonery against Nobunaga and attacked him at the Honnoji Temple when he was off-guard.
Since then, Tama was labeled as "the traitor's daughter" for her whole life and led a tragic life. Her father in law suggested to kill her as well, but her husband let her escape to the mountains and she stayed there for 2 years. She finally returned to the Hosokawa family later, then, she became a Christian and her baptismal name is Gracia. But another tragic fate awaits for her...
In past adaptations, Hosokawa Gracia had a big role and was quite a focus during the Akechi Mitsuhide's treasonery and right before the Sekigahara battle. She has been acted by Suzuki Kyoka (AOI Tokugawa Sandai - NHK Taiga 2000) and Hasegawa Kyoko (Komyo ga Tsuji - NHK Taiga 2006), so far.
Hosokawa Gracia is 10 years older than Gou. In the "GOU" novel written by Tabuchi Kumiko, Gou is well-acquainted with Tama when she still live with the Oda family. Tabuchi made a comment in the news article, "I would like to write that Hosokawa Gracia is someone Gou look up to and admire,".
I'm very pleased with this casting!!^v^ I think Mimura can play the role even better than Hasegawa Kyoko! Hosokawa Gracia is usually portrayed as a gentle woman but strong in facing her tragic fates. I think the role is perfect for Mimura. I would like to say that I think she can act it better than Suzuki Kyoka too, but that won't be too fair coz Kyoka only had 1 (crucial) scene in AOI.
As this drama is about the Sengoku princesses, I think Hosokawa Gracia is like the 5th princess next to the 3 Azai sisters and their mother. I'm sure she will get a lot of focus.