This had all started with a trip to the grocery store. Yukina had decided that if she was going to live in this world, she should probably learn how to function in it. So the girls took her out on a shopping trip because really, how much more mundane can you get than grocery shopping. It had been a strange experience but it went surprisingly well, no small thanks to the clerk. Onna was someone Keiko knew from school, the same age as she and Yusuke but not close enough to really be considered a friend. It was certainly strange to her, someone who seemed to be as old as they who didn't know about money or what things were called She must be a foreigner Onna thought, for how could a Japanese woman not know such things, but she assisted her with a smile for which Keiko was grateful. She welcomed Yukina to come back any time and she would help her with anything she needed. One shopping trip turned into several, which led to days off together and nights on the town. The group soon got along famously, laughing together and the girls almost forgot that some of them were different, not human.
The first time they encountered a demon, Onna blinked a few times, rubbed her eyes, and apologized saying she must not be feeling well and should probably get home to bed. The second she asked if the others had seen it as well and by the third a few things had to be explained. After that there were a lot more nights spent together at the temple. She met Kurama, and Hiei, both caught her attention but in her own words a relationship wasn't something she was had time for. Kurama was rarely present but Hiei seemed to take a dislike to her immediately, constantly harassing her about her 'intentions' with Yukina. Onna took offense at this and soon they could hardly be in the same room without harassing each other. Then the boys went away.
She wasn't sure why they'd gone, she never asked, but they were gone for close to a month and she found she missed them more than she thought she should. She busied herself with work and spending time with the girls, even took a second job working at Keiko's parent's shop, but it wasn't quite the same. She wasn't there when they came back so she was surprised at the increased number of familiar faces she encountered when she reached the top of the stairs to the temple. Things soon returned to normal, though the fighting between Hiei and Onna lacked its usual barbed edges. They went away a few more times, though never as long, and she met Botan and Koenma, started learning basic martial arts. 'I have to keep up with you guys somehow' she'd joked.
At some point a heated argument about whether or not she'd been flirting with someone, or if he'd been flirting with her, turned into an unexpected and uncomfortably public makeout session.
The new development led to even more arguments between the two but everyone noticed a smirk from Hiei more often, and a playful sparkle in his eye. Everyone agreed it was probably the happiest they'd seen him. They carried on for a while and it seemed to everyone that it would last. Keiko got married, Yukina got married, Genkai got older, and Hiei disappeared.
Onna didn't say much about the subject, just reminded everyone that she was a human and that he couldn't really be expected to deal with her getting older while he stayed the same forever. It upset her, but she'd get over it she told them, and threw herself into work once more. When she started getting sick she simply chalked it up to stress and told everyone not to worry and that she would take a few days off of work. Only it didn't. When Hiei finally turned up again she had grown quite round, and subsequently rather hormonal, and the fight that ensued while not pretty, was cathartic. The two became happy, tentatively discussed the future, and dared to make plans. After many hours of grueling labor the baby girl they had made together, however accidentally, had never cried. The cord had gotten wrapped around her tiny neck, and the little life was lost. The two would-be parents held her and talked quietly to each other of several hours before they held a small, private ceremony and burned the tiny body.
Onna was withdrawn for a long time after that, but Hiei rarely left her side and eventually a glimmer of the playful independent woman they had known resurfaced. Surprising everyone, the two married. When asked what she did she simply told them that she 'asked the right question' and left it at that.
Many years and children later when she was getting older and her Hiei was still young and full of fire she tried to get him to leave but he refused, even when she threatened to turn into Genkai and keep growing older but never die he simply told her to go right ahead.
Later, when she finally did pass after a long and happy life all he told their children was that he had loved her, even when she was no longer young and beautiful.
It's 4am and this plot bunny hasn't left me alone for at least a week. I may decide to write chapters, talking a more 'moments' approach than this drabble but for now it is what it is. Loosely inspired by the song Young and Beautiful.
If anyone wants to take this idea and make it into a full fledged story PLEASE feel free to do so. Just send it to me because I'd love to read it :)