Siscon

Siscon or Sis-con (also known as incest) is a phenomenon started by the Japanese which centers on incest between siblings. It was created by sick people who get turned on while looking at their family album. Even so, Siscon isn't going anywhere and is slowly corrupting the human population. The show Onii-chan Dakedo Ai Sae is an anime about sisters who want in their brother's pants.