There are also poem about "Three Hanzos" which attributed to him as part of three Tokugawa's notable warriors: [4][5][6][7] It was recorded that Moritsuna using the European style (Nanban Do Gusoku) armor set, with Spanish Morion helmet and one piece body plate.

[9] Watanabe Moritsuna joined the Ikkō-ikki rebels in Mikawa along with his father Takatsuna, and for a time became an enemy of Tokugawa Ieyasu.

After the uprising subdued by Ieyasu, Moritsuna were pardoned and returned to join the Tokugawa clan rank.

Later in 1573, during the Battle of Mikatagahara, Moritsuna and Hattori Hanzō performed with exceptional skill with their spears.

[17] After the Siege of Odawara (1590), Watanabe was given control of domain in Musashi of 3,000 koku and also command of 50 ashigaru infantry.