Most of the characters in Bel Canto use Watanabe as a means of communication. Watanabe has a great gift for languages, and helps the hostages understand one another and the terrorists. Despite his facility with languages, Watanabe has a hard time expressing his own thoughts and emotions.
Although the terrorist Carmen cannot read or write, she is passionate about words, and Watanabe falls in love with her partly because of her intense desire to master the language. Watanabe’s love for Carmen allows him to become a person in his own right, instead of the quiet interpreter who serves everyone else.
Watanabe also functions as a symbol of language. Like language itself, Watanabe both facilitates and impedes direct communication. People cannot communicate without him, but he is almost a third wheel in conversation, an impediment to heart-to-heart talks.