Answer:
He believes they are dangerous.
Step-by-step explanation:
The Heart of a Samurai by Mergi Preus is based on the true story of a young Japanese boy named Manjiro Nakahama who became the very first to reach America. Left adrift on an isolated island, Manjiro had always dreamt of becoming a samurai which is only possible through inheritance. But his actions of staying in America after being rescued by Capt. Whitfield and his return to Japan were honored with the title of a samurai.
In the given excerpt/ conversation, Gaemon's attitude towards the Americans is revealed. He believed that they are "barbarians" who will torture them, pointing out the weird way they are made to sit in benches, which is not the way they (Japanese) used to sit. This given conversation reveals that Gaemon believed the "barbarians" to be dangerous.