When we first came across the title The Eye, the Ear, and the Arm, we were a little confused. What, no nose? It didn't take us too long to figure it out though: The title comes to us directly from the names of the detectives who help find Tendai, Rita, and Kuda. That said, these aren't your average detectives.
For one thing, they look different. Listen to the way Arm describes it:
"There isn't anyone like us," said Arm. He extended his hand, and Mother, with only a tiny pause, shook it. She felt the strangest sensation as she grasped the fingers—and not only because they were slightly sticky. (6.36)
Strange sensation? Sticky fingers? Yeah, something's a little different here. For another thing, these dudes have superpowers when it comes to the senses. So we figure out pretty quickly that Ear, Eye, and Arm do things a little differently. Luckily, their wacky sleuth skills help save the day.
The title helps us focus on this motley crew of detectives and their unique skills—even if we don't have huge ears or laser eyes. It also reminds us that being different isn't a bad thing. If wonky-looking, hyper-sensitive detectives from the middle of nowhere can help rescue Tendai and his siblings, then perhaps Tendai has some mega value, too.