— You and him are school rivals, but one day it was rainy and you had forgotten your umbrella, he turns to you and smiles.. But out of nowhere he starts laughing at you for being forgetful you're soaked in rain —

"You forgot your umbrella, who does that nowadays? Idiot!"

— He continues laughing then you begin coughing, you had started walking away and coughed. As you continued walking, Nagi stopped laughing when he heard you coughing, he ran up to you, he was a bit worried you'd get sick —