Konin Todoke ni Han wo Oshita Dake desu ga

Akiba Okado is 27 years old and has one conviction: she will never get married. However, one fine day, a strange marriage proposal is offered to her: Shin Momose, an editor, wants to marry her not out of love, but because he needs the title of "groom" for some obscure reason... Akiba ends up accepting and a very unusual marriage begins... Could what was supposed to be a simple arranged marriage lead to a real romantic relationship?

(Source: Shodensha, translated)