SPIKY TEA BOWL

Sen no Rikyu, the great master of wabi-cha whom Koga respects, is said to have used black tea bowls to erase their presence and let the tea itself stand out.
Moved by this, Koga deliberately champions “Anti-Wabi-Sabi”—an approach meant to heighten a work’s presence. How can the power inherent within an object be made visible, expressed as something radiating overwhelming presence?
One answer Koga arrived at was studs.
"As the smallest unit of force, I found it an interesting shape — one that acts on sight, touch, and even taste."

The matcha bowl is handled by cupping it with both hands.
In other words, one could say the effect of the studs is easier to feel than on something handled with one hand.
"Anti-wabi-sabi" is the concept Koga champions. Within it, the "matcha bowl" holds particular significance.