Though only vaguely connected to Japan I want to introduce you to “Dark Waters” from Rain Oxford, the first book of her Elemental series.
Rain Oxford is a teacher who has been writing for more than half of her life. The Asian-influenced cultures she creates were inspired by Japan, where she attended Ritsumeikan University in Kyoto. She does most of her writing in a secluded cabin in the woods with a four-pound Maltese as a companion. When she’s not teaching or creating worlds, she usually enjoys cooking, playing the piano, or photographing exotic wildlife.

Dark Waters by Rain Oxford
When Devon uncovers a violent murder, he knows it is not a natural crime. In order to solve this case and expose the murderer, he will have to go undercover as a wizard in the paranormal university, Quintessence. He soon discovers that his talent has more to do with supernatural forces than he ever knew.
Devon Sanders and his roommates Darwin and Henry are interesting characters and I can’t wait to see how they will be evolving over the next books. Anyone who loves magic and a good mystery novel should give Dark Waters a try. (Available on Amazon)