On top of the elemental weapons that Samanosuke can acquire, he can also get two ranged weapons: A Bow (Yumi) and a Matchlock firearm (Teppo).
The bow and arrow was the traditional weapon of the samurai and had been in use in Japan since the ancient days. Samanosuke was also able to find and use Flaming Arrows, something that samurai armies liked to use against fortifications and buildings as they were made predominantly of wood.
The matchlock firearm, or Arquebuse, was introduced to Japan with the arrival of Portugese sailors and missionaries in the early 16th century. During the time that Onimusha: Warlords is set they were still not yet in vogue; although Samanosuke's enemy in the game (Oda Nobunaga) was one of the idea-men leading the charge to revolutionize samurai warfare with their integration into peasant conscript armies.