My Second Life with My Childhood Friend in a Western Fantasy World

The most painful thing in the world is transmigrating into a Western fantasy world with your childhood friend and sworn enemy. A flying red dragon, a labyrinthine underground maze, a portal to another world atop the mountains, and... the girl who never stops bickering with me. But ever since we transmigrated, my childhood friend has become a blonde girl, and seems to have inherited some sort of tsundere trait. “Hey, since we're short on money, I'll reluctantly share a bed with you!” “Hey, since the Ring of Oaths can make me stronger, I'll reluctantly let you put it on me. Remember, it goes on the ring finger of my left hand!” “Hey, since what happened that night already happened, I'll reluctantly spend the rest of my life in this world with you!” Wait, this plot isn't going the way it should. This isn't tsundere, it's super-duper tsundere!