I want to marry you, so please let me ○○○○.

"I'll marry you, so please let me graduate high school." I'm an ordinary unmarried salaryman, and through my sister's introduction, I receive a marriage proposal (or plea?) from Sudo Yui, a beautiful girl more than 10 years younger than me... Isn't this the same as compensated dating? But still, I want to somehow save her from her difficult living situation. However, my earnest girlfriend refuses one-sided assistance. Before I know it, my sister is scheming one thing after another behind my back. And then my girlfriend's behavior becomes strange too!? This is a dreamlike story that befell a serious, prudent, frugal, and unfortunate man. ※Please, sensible high school girls, do not imitate the heroines of this work. ※Marriage, regardless of how it comes about, is an act of building a mutually responsible relationship. Proceed with the resolve to take on that responsibility.