My Three Wives and a Cheat System

Modern food delivery guy Leo Leighton travels through time to the northern border and awakens a favorability system, exchanging modern supplies/abilities. He solves food/warmth problems, eliminates bullies, fights a tiger. He uncovers The Four Great Families' conspiracy to embezzle military funds and raise rebel soldiers. With a Princess's help, he overcomes perils with system support and strategies, pacifies northern border troubles, becomes commander of three armies. He gives up returning t...