One great 'Yugioh Female Hikari' fanfiction is 'Hikari's Journey'. It focuses on Hikari's growth as a duelist in the Yugioh world. The story has really well - developed characters and interesting duels.
Yes, there are likely some fanfictions out there about Hikari and Kei getting married in the Special A universe. You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just type in relevant keywords such as 'Special A Hikari Kei married' and you might find some interesting reads.
I'm not entirely sure as I haven't played it specifically. But generally, a visual novel often involves a story with characters, plotlines, and usually some form of choice - making for the player. It might be about a journey in search of light, as 'hikari wo motomete' can be translated as 'in search of light'.
There are likely some out there. You can start by checking fanfiction websites like Archive of Our Own or FanFiction.net. Search specifically for 'Special A Hikari pregnant' and you might find a variety of stories with different takes on the concept.
One common theme could be adventure. Since both characters are from the Pokémon world, they might embark on new Pokémon - catching adventures together. Another theme might be friendship development. They could start as acquaintances and gradually become really close friends through various experiences.
You can start by looking on fanfiction.net. It has a large collection of Yugioh fanfictions, and there are bound to be some great ones about Female Hikari there.
One interesting 'fairy tail hikari fanfiction' story could be about Hikari going on a special adventure with the main Fairy Tail characters. Maybe she discovers a hidden magic that only she can control and uses it to save the guild from a powerful enemy.
One possible plot could be their adjustment to married life. Maybe Hikari is still as headstrong as ever and Kei has to find new ways to deal with her. For example, Hikari might take on a big project at work and Kei has to support her while also managing his own business affairs. Another aspect could be their family planning. They might discuss having children and the challenges and joys that would come with it.
Often, there might be themes related to family. Since Hikari is pregnant, there could be exploration of how her family and Kei's family respond. There may also be themes about the future, like what kind of parents they will be and how their relationship will change with the new addition to their family. And of course, there could be themes of love and support during this big life change.
There could be a 'kei and hikari baby fanfiction' where the baby gets lost in a magical world. Kei and Hikari then have to go on an adventure to find their baby, meeting all sorts of interesting characters along the way. They face challenges that test their love for each other and their determination to get their baby back.