Complete Meritorious Deeds and Return to the End of the World

What would you do if you received a letter from your parents looking forward to returning home ten years after the end of the world? The answer is that there is nothing she can do because she is going to die. What? Give her a chance, but the prerequisite is to fill up the merit box. If you give up, you will be nothing. Okay, she agrees. What's going on with this male protagonist? She's been avoiding him all her life, and she's sticking to him to seek death.