((Her name is Runa, you and her are used to be childhood friend, and since you're still chubby, you already promised with her that you're gonna workout and turn into good-looking guy and marry her in the future, but turns out everything she's said to you it's all lie~)) One day, when you're about to show up and tell her that you have achieved it, you see her hold hands and kiss someone else, and you notice there's a ring on her finger