Tokugawa Soyo also known as Soyo Hime (そよ姫) is the younger sister of Tokugawa Shige Shige.
Since her father died, Rotten Maizou has served as her guardian and she views Maizou as a fatherly figure.
After her brother died, because of the poison caused by one of Nobu Nobu's assassin, Soyo Hime becomes depressed.
Her height is 156 (5' 1 1/2") cm and her weight is 40 kg. When she disguise herself as a normal civilian, she wore a green kimino with orange patterns. Soyo Hime is 14 years old the same age as Kagura.
Spent half a day with the 'Queen of Kabuki District' Kagura when she escaped from the palace due to boredom and loneliness, and got hooked on sukonbu as a result.
Courtesan of a Nation Arc
Sakata Gintoki was asked by Tayuu Suruzan to help her look for the man who made a promise to her. Yorozuya and Hyakka went looking for clues until they speculated that the person they're looking for was the former Shogun.
She helped Yorozuya and Tsukuyo to enter the castle. Soyo Hime was thrilled to see Kagura again, although Rotten Maizou thought it was improper for her to act like that. Gintoki was shocked when Kagura knew a higher status person than him.
When Yorozuya, Nobume and Tsukuyo found out Tokugawa Sada Sada was using Suruzan as a bait for assassinations, Sada Sada used this opportunity to order the Naraku to assault Sasaki Isaburo and frame it on Yorozuya, Tsukuyo and Imai Nobume.
Yorozuya, Tsukuyo and Imai Nobume were thrown in prison waiting for their execution. When things became hopeless, Soyo Hime at the time felt lonely so she sneaked in the prison while the Shinsengumi fought amongst itself to create a diversion. Soyo Hime told a story that involves the promise between Suruzan and her lover. It turned out that it was Jiiya who made the promise.
After hearing that Jiiya was the servant that had to endure Tokugawa Sada Sada's punishment. She wanted to help Jiiya no matter how many times he'll scold her but ended up unconscious due to her klutziness. Kagura hid her in a bush.
After waking up, she rushed to Jiiya's side and was relieved that Shinpachi and Kagura protected him from the guards. She was glad that she didn't lose another father. The Shogun wants Jiiya to go to Suruzan to keep his promise and asked Soyo to take care of Jiiya before confronting his uncle.