Japanese are difficult to deal with.
It sure was a process to get them to release on Spotify. Before that they tended to stay on Apple Music.

Examples of artists I liked:
Tokyo Health Club - J-Rap but a bit more lo-fi
-> One of my favs: https://youtu.be/GSRfeUHZZN8
-> Honorable mention: https://youtu.be/ErLSUsqERm8

• Crazy Beats (Touhou - Eurobeat Remixes)
  -> Just open any of their songs and listen ;)
• Akatsuki Records (Tohou Remix - All kinds of genre)
  -> Same here
• Hololive (A group of vTubers that also release music of all kinds of genre)
  -> https://youtu.be/twUFbqyul_M
  -> https://youtu.be/WGgEFoI9MhE
• Ado (Also very diverse voice and genre selection. But usually more towards pop and pop-rock-like releases)