Shinju 真珠
Japanese for pearl; in rope, a name for a chest harness that emphasizes the breasts, for which Shibari Study suggests the term munenawa.
Shinju (真珠) is the ordinary Japanese word for pearl. In rope it names a chest harness: Rope365 lists it as another name for the chest harness, and English Wikipedia describes a breast harness with rope passing above, below and between the breasts and looping over the shoulders behind the neck, while reporting that no tie called shinju is found in historic or present kinbaku. Shibari Study says the word is often used for harnesses that emphasize the breasts and suggests munenawa (chest rope) as the more linguistically fitting term.