bauble, jewel
珮 centers on a decorative personal ornament, specifically a jewel or bauble worn on a sash or belt.
珮 combines 王 (jewel) with a phonetic component that also appears in 佩, suggesting an ornament worn on the body. The exact historical development is uncertain.
The left side 王 (jewel) and the right side resembling a sash (巾) with a hanging ornament (几) together picture a jeweled bauble dangling from a belt.
For ハイ, imagine a high-society person wearing a jeweled bauble: high -> ハイ, and the jewel sparkles on their sash.