At a very young age, Katsunaga, then known as "Gobomaru", was given in adoption to Toyama Kagetou and his wife,
Lady Otsuya, at
Iwamura Castle. Lady Otsuya was Oda Nobunaga's aunt. In 1572,
the castle was captured by
Takeda forces under
Akiyama Nobutomo, and Gobomaru, then four years old, became a hostage of the Takeda. In 1581,
Takeda Katsuyori released Gobomaru (Katsunaga) to the
Oda clan, who returned him to
Iwamura Castle, which had been re-taken during his absence. ==Honnō-ji Incident==