Another option could be to check with libraries. Some libraries have a collection of international literature, including light novels. You can ask the librarian if they can order it for you if they don't already have it in their collection.
You can try looking for it in local bookstores that specialize in Japanese literature or light novels. They might have a section dedicated to such works.
I'm not sure specifically as I haven't read it. But generally, a light novel often involves unique characters and a fictional story. It might be about the adventures, relationships, or personal growth of the characters within the world created by the author.
You can start by looking on fanfiction.net. It has a large collection of various fanfictions, including ones about Kenshin and Kaoru. Just use the search bar and type in 'kenshin x kaoru' and you'll get a bunch of results.
Some dedicated anime and manga fan forums might also be a good source. For example, Reddit has several sub - forums related to anime and fanfiction. You can post a request there asking for 'Kenshin Himura Crossover Fanfiction' and chances are someone will be able to point you in the right direction. Additionally, Tumblr can sometimes have great fanfiction recs, especially if you follow the right tags and blogs related to Kenshin Himura.
Some dedicated anime fanfic forums might also be a good source. For example, AnimeFanficForum. There, fans often share and discuss their favorite fanfics, including those centered around Kenshin and Kaoru's love story.
Archive of Our Own (AO3) is also a great place to look. There are many different tags and filters you can use to narrow down your search for this specific type of fanfiction. Just search for 'Kaoru Kenshin watcher' and see what comes up.
Fanfiction.net is also a great place. It has been around for a long time and has a vast collection of fanfictions. Just use the search function and look for 'kenshin and kaoru love'. However, the quality may vary, so you might need to read through a few to find the ones that really suit your taste.
Fanfiction.net is also a good place to look. There are many authors who write about different aspects of their relationship. Just be sure to read the tags and summaries to find the ones that interest you.
This book was called "I'm a Sword God in Tokyo." The characters in it included the male protagonist, Kiritani Kenshin. This book can be read on Qidian Chinese website. [I Am a Sword God in Tokyo] Author: Qingyu Nianye. It is a light novel/original fantasy novel. It has been completed and can be enjoyed without worry. [User recommendation: Reborn to Tokyo, Japan, becoming the last disciple of the dojo.] Kiritani Kenshin only wanted to eat, earn money, and play with his sword, but he did not expect to be sold by his master to Fei Yang Spirit Cleansing High School. There were ninjas, swordsmen, priests, witches, and onmyoji. In order to eat and sleep well, in addition to attending classes every day, he had to frequently accept commissions to subdue demons and earn a little money. Monsters, vengeful spirits, evil spirits, gods… The night of a hundred ghosts made the world tremble. At the age of sixteen, Kiritani Kenshin stood there like a minion. He swore to himself that he would definitely become the new generation... Old Master Tong! …… "This Sword God is obviously very strong but is overly black-hearted","The Spirit-Killing Life from Zero", and "The Daily Life of the Sword God". I hope you will like this book.
There might be. A lot of fanfiction explores crossovers and unique concepts like this. For FanFiction.net, create an account if you don't have one already, then search for 'Naruto is Kenshin Himura'. Archive of Our Own also has a large collection. You might have to dig a bit through the search results as not all stories will be exactly what you're looking for, but it's a good start.
This book was called "I'm a Sword God in Tokyo." The characters in it included the male protagonist, Kiritani Kenshin. This book can be read on Qidian Chinese website. [I Am a Sword God in Tokyo] Author: Qingyu Nianye. It is a light novel/original fantasy novel. It has been completed and can be enjoyed without worry. [User recommendation: Reborn to Tokyo, Japan, becoming the last disciple of the dojo.] Kiritani Kenshin only wanted to eat, earn money, and play with his sword, but he did not expect to be sold by his master to Fei Yang Spirit Cleansing High School. There were ninjas, swordsmen, priests, witches, and onmyoji. In order to eat and sleep well, in addition to attending classes every day, he had to frequently accept commissions to subdue demons and earn a little money. Monsters, vengeful spirits, evil spirits, gods… The night of a hundred ghosts made the world tremble. At the age of sixteen, Kiritani Kenshin stood there like a minion. He swore to himself that he would definitely become the new generation... Old Master Tong! …… "This Sword God is obviously very strong but is overly black-hearted","The Spirit-Killing Life from Zero", and "The Daily Life of the Sword God". I hope you will like this book.