Kazarinawa 飾り縄
Decorative rope: rope added at the end of a tie, often from the leftover length, to finish it visually rather than to hold its structure.
Kazari means ornament and nawa means rope; the term is also written kazari nawa. Shibari Study and Andrea Ropes both describe it as rope that decorates or finishes a tie without forming part of its structure, usually made from the rope left over at the end. Kinbakuwiki, writing about kazari more broadly, adds that such details vary a standard pattern and can also keep the interaction going through added pressure or movement. It notes that symmetrical styles favor symmetrical ornament, while Yukimura-ryū and Naka-ryū often prefer asymmetry. Japanese Wikipedia mentions the kikkō pattern sometimes being used purely as decorative rope.