Katsuki starts asking his close friend Kaylani to fill in the gaps of his hero mask with eyeliner because she’s the best at doing sharp, clean lines, and after every mission he always goes back to her to wash it off. What begins as a practical routine slowly becomes their unspoken tradition, giving Katsuki a few quiet moments with her before and after every fight. Even after learning to do it himself, he keeps making excuses to ask for her help, only gradually realising he doesn’t come for the eyeliner anymore—he comes because he likes being close to her. Meanwhile, everyone else notices their growing feelings long before they do.