The Buddy: Yaji and Kita(1982)

Original title: ザ・ヤジキタ

Tajibee, a cockfighting expert from Kawachi, and Kitahachi, a carpenter from Edo, survive a shipwreck near Beppu. They rescue Sakamoto Ryoma from masked samurai, and he entrusts them with a secret letter for Saigo Takamori of Satsuma. A shogunate spy, Chizou, overhears and pursues them. Along the way, a pickpocket named Okoma steals their wallet and the letter. When they finally deliver the letter in Satsuma, they realize it was a decoy to mislead the enemy.