Online platforms could be a good place to look for the '29 sai dokushin light novel'. Websites like Amazon might have it available for purchase in either physical or digital format. Also, some specialized e - book platforms that focus on Japanese light novels could potentially have it in their catalog.
Another option is to check with libraries. Some libraries have sections for international literature, and they may include Japanese light novels. If your local library doesn't have it, they might be able to order it through inter - library loan systems. Additionally, there could be some fan - based communities or forums related to light novels where you can ask for more information on where to find this particular one.