year of Takechiyo's birth, the Matsudaira clan was split. In 1543, Hirotada's uncle, Matsudaira Nobutaka defected to the Oda clan. This gave Oda Nobuhide the confidence to attack Okazaki. Soon afterwards, Hirotada's father-in-law died, and his heir, Mizuno Nobumoto, revived the clan's traditional enmity against the Matsudaira and declared for Oda Nobuhide as well. As a result, Hirotada divorced Odai-no-kata and sent her back to her family. Hirotada later remarried to different wives, and Takechiyo eventually had 11 half-brothers and sisters. Hostage life As Oda Nobuhide continued to attack Okazaki, Hirotada turned to his powerful eastern neighbor, Imagawa Yoshimoto for assistance. Yoshimoto agreed to an alliance under the condition that Hirotada send his young heir to Sunpu Domain as a hostage. Oda Nobuhide learned of this arrangement and had Takechiyo abducted. Takechiyo was five years old at the time. Nobuhide threatened to execute Takechiyo unless his father severed all ties with the Imagawa clan. However, Hirotada refused, stating that sacrificing his own son would show his seriousness in his pact with the Imagawa. Despite this refusal, Nobuhide chose not to kill Takechiyo, but instead held him hostage for the next three years at the Honshōji Temple in Nagoya. It is said that Oda Nobunaga met Takechiyo at this place, when Takechiyo was 6 years old, and Nobunaga was 14 at that time. In 1549, when Takechiyo was 6, his father Hirotada was murdered by his own vassals, who had been bribed by the Oda clan. At about the same time, Oda Nobuhide died during an epidemic. Nobuhide's death dealt a heavy blow to the Oda clan. In 1551, an army under the command of Imagawa Sessai laid siege to the castle where Oda Nobuhiro, Nobuhide's illegitimate eldest son was living. Nobuhiro was trapped by the Imagawa clan but was saved by Oda Nobunaga, Nobuhide's second son and heir, through negotiations. Sessai made an agreement with Nobunaga to take Takechiyo back to Imagawa, and he agreed. So Takechiyo (now nine years old) was taken as a hostage to Sunpu. At Sunpu, he remained a hostage but was treated fairly well as a potentially useful future ally of the Imagawa clan until 1556 when he was 14 years old. Service under Yoshimoto (1556–1560) In 1556, Takechiyo officially came of age, with Imagawa Yoshimoto presiding over his genpuku ceremony. Following tradition, he changed his name from Matsudaira Takechiyo to . He was also