Figuring out the decorative elements on a cosplay can be a challenge, there are often buttons, or fastens or just pretty bits that are stuck on in odd locations.
Orochi’s knot that appears on the front of her top was one such detail. It is
possible to just cut the loops and glue or tack them to look mostly correct. However, I approached this one from the idea that the artist likely drew it from a real knot, so I did a google search for a three loop frog knot, as it appears in the approximate location of a fasten.
I found the video: https://www.youtube.com/watch?v=7LcRVGq9lzo
Which is a knot that was used on the temple good luck charm that is shown next to it. It seemed likely to me that this was the source of the inspiration for the knot. Orochi’s knot only had single loops not the double loops, so I followed the instructions on the video using a single strand of the cord and came up with the knot pictured here.
Simple and makes sense with the culture and location of the character. Artist often use things they see everyday as a visual inspiration for what they draw.