"Yes, if a man and a woman like us can be friends, surely I want to be your friend. What do friends do? Let me see: Real friends do each other favors even when it's inconvenient; and expect nothing in return. Friends are sincere when you're being ridiculous, but they support you when you really need it. Friends count on each other, right?"
Ye Rim could no longer control the conversation after that, and could only agree, stunned, that from now on they were friends. Not just 'friends'. But 'good old friends,' as he insisted. They would have carte blanche to call each other, ask for favors, and exchange confidences. Respecting the limits of decency, since they could not deny their genders, they naturally had complete freedom with each other. Only then could the 'Friendzone Experiment', as he called it, prove who was right.