"Ah, I didn't start it on purpose. Or really start it at all, I guess, though it was my actions that caused it to escalate the way it did, so I had to take responsibility."

Mikado is already realizing that he probably shouldn't have said anything, but there's no point in lying about it here. He flushes and shifts from one foot to the other awkwardly.

"At home, right before coming here, I decided that course of action I had to take to end that war, so since I'm here instead, I should at least become stronger in preparation for that. That's what I decided."