A teenage boy has pleaded guilty to repeatedly raping a woman while armed with a tomahawk during a home invasion in Cairns last year. The 16-year-old, who cannot be named, faced the Children's Court in Cairns by video link from a detention centre for an arraignment hearing today. The court heard the boy committed the armed home invasion with two other teenagers at Manunda in Cairns's inner west. One of the other boys, now aged 17, was armed with a knife, the court heard.