Antenna is the story of Yuichiro (Kase Ryo), a graduate student "researching" the philosophical aspects of his experiences at S&M clubs. Yuichiro is haunted by an event from his past that he cannot shake - the disappearance of his younger sister 15 years ago - and it soon becomes obvious that his dark psychological state is directly linked to the disappearance.
His family has been affected as well. An uncle, a suspected pedophile, committed suicide soon after the disappearance. His mother has turned to religion and superstition in an effort to deal with her pain. And his little brother, born after the disappearance, appears to sense the presence of his sister with an internal "antenna."
