Ghost of Tsushima: Emperor's Tears

Ghost of Tsushima's Emperor's Tears is a sword kit with the description "Pure of purpose, prepared to face death" It is one of the appearance upgrades for the Sakai Katana that you can buy from merchants.

Pure of purpose, prepared to face death.

Acquiring Emperor's Tears

You can buy it from merchants at the cost of 15 flowers.

Merchants sell not only sword kits, but also bow kits, armor dyes, and hats. 

Visit our Ghost of Tsushima 100% Walkthrough to get more details.