During the Sengoku Period (period of warring states), when a battle required a long stay at the front, a lord would choose attractive boys among his Kosho and practice various kinds of sexual acts with them, such as anal intercourse, in order to vent his sexual desires.
戦国時代においては、主に合戦や長期に渡る滞陣中に性欲を発散するため、主君が小姓のうちより美貌の者を選んで、肛門性交などを始めとする様々な性行為を行われていた。