"The chairman chose us," he said. He chose them because they had Charas. Which he... hadn't had when he was made a Guardian. Strong feelings of a lack of self worth, self disgust. The egg stopped moving.

And of course Nagihiko had been partially lying. He had been tapped personally. But he hadn't chosen Amu directly by the Chairman. Instead Amakawa-san had told them to watch for a child with three eggs....