 If you liked Mushi-Uta |  ...then you might like Tegamibachi |
Both have the same idea. In Mushi-Uta, the Mushi (insects) are able to consume people's dreams and thoughts. In Tegami Batchi, the Gaishou (also insects) eat people's feelings and emotions. After they devour people's thoughts and feelings, people become like dolls! They don't talk, speak, or show any reactions. They are alive but dead inside!