Matsumoto Yisano ( aka Yoko ) & Sora Ryuuji.
Ryuuji comes from a lower noble family, where he was next in line to be the head. His family were in charge of the archives, pretty much making sure to chronicle everything happening within the history since the beginning of the seireitei. They also served under the Kyouraku Clan. When his Father, Sora Hayate, was exiled he became the head of the family and continued to do his duties.
Meeting Yisano happened purely accidentally. While completing a meeting with a meeting with one of the Kyouraku Clansmen, he passed by the 11th and saw a woman beating down another officer. Of course, sparring was pretty much every day life for those who wanted to keep their skills sharp. But this woman was rather ferocious for someone who barely broke five feet.
No one would call it love at first sight, absolutely no one. It was more like lust at first sight. That level of power, how feral she seemed made for intense passion. And for awhile, it’s all it was. A Fourth Seat in the 11th Division under the First Kenpachi and the Head of a Noble family didn’t seem like a good match. Somewhere along the way, it became love. Marriage had never crossed their minds but eventually it did happen, despite the protestation of some of his Clansmen, because she seemed too wild, and unrefined. But they did get married.
No one can say happily married since they did argue sometimes, but relationships, especially Shinigami relationships aren’t perfect. A few centuries down the line, Yisano ended up pregnant. As most know, getting pregnant in the Seireitei isn’t as easy as most would assume, and yet Yisano ended up pregnant. The pregnancy was a peaceful one and they both seemed to find another purpose other than the fighting each other. During birth, when they found out it was twins, it had been a surprise for both of them. A boy and girl they named, Rangiku and Ren.