Read The Cannon Fodder Princess Wants To Last manga
On the way to escape the marriage, the heroine fell into the lake due to a miscalculation of a math problem, and passed through to the former princess Mu Yunkai who was being hunted down. As long as the system settings are full, you can return to the original world and live again! I thought this as a journey full of happiness with beautiful men, but why do all of them want… to kill her?
Princess Cannon Fodder Wants To Last / 炮灰公主想苟到最后