Term shinju is used to refer breast harness in Japanese bondage. Its meaning is "pearls" as "nipples" or "breasts". "The origin of this term is one of two European Webmasters who both claim to have made up this name for a chest harness tie." (says Tatu). It is western term, not used in Japan related to Shibari.
I use this term to describe ropes going over breasts or going between breast!
Usage for my ties
I use this term as a part of extended version of Takate kote (Hands tied behind back), where ropes lead from back, over shoulders to breasts; very often these ropes contract wraps under breasts upwards.
I usually do not tie shinju separated but as a part of Takate Kote.
Shinju excluding hands
Now I tried to do shinju separately, excluding hands. So I can explain some principles, but this examples need not to be the best ones.
There are more ways how to do it.
I used 10m of rope but you can use 9m also.
Here I start from back. Make Lark's head: Make wrap around torso, over breasts. You can change direction and make another wrap or don§t change direction (then we must to make a lock if we want to go down to lower wraps).
Then I do lower wraps. Then I create a stem.
Then I create front lines to stretch the horizontal wraps. I can use Munter hitch to bind the wraps together. I go back and finish.
See my ties in my tutorials.