Wanko-Kei Osananajimi no Kishi ga, Otto ni narimashite

Alan, a crybaby childhood friend who is like a younger brother, and Tina, who has been like a loving older sister. Alan grows up to become a knight in the royal capital and rises to the rank of captain of the Kingsguard. One day, however, Alan returns to the village in a great hurry after his success in defeating the demons, and says, “I’m so lonely, I’m going to die!” By the time Tina had taken in the situation, she was living as a “wife” in a mansion in the royal capital. They had not even been lovers for a long time, and now they are told to slowly become husband and wife…and then mysterious honeymoon planner shows up.
まるで弟のような、泣き虫な幼馴染アランと、世話を焼く姉のように過ごしてきたティナ。
成長したアランは王都で騎士になり、近衛騎士隊長にまで出世する。しかし魔物大討伐で活躍したアランが、ある日、大慌てで村に帰ってくると「寂しすぎて死んでしまう！」という理由でティナとそのまま入籍をしてしまって！？
ティナが状況をのみ込んだ頃には、王都の屋敷で“奥様”として暮らすことに。
恋人の期間もなかったのに、ゆっくり夫婦になろうといわれても――さらには謎の新婚プランナーまで現れて……。