Japanese Scales Are Mostly Covered By Ragas
The Miyako-bushi scale, a Japanese traditional scale, is in Gunakri/Gunkali.
Enka or the like is sung in Bhupali.
The exception is the Okinawa scale that I have never heard of the raga.
In Japan each music piece is enjoyed, for example, “Rokudan no Shirabe” written in the scale of Miyako-bushi, “Hakodate no Hito” composed in the scale which omits the 4th and the 7th, etc.
In India, every music piece (Bandesh) is just the basis for improvising each raga itself, consequently Ragas, that is to say, the scales are focused more.
Not only the scales but many things have in common, “jawari” of India and “sawari” of Japan are almost synonymous. Like biwa (a four or five stringed Japanese lute) and shamisen, which sawari is set to the string(s) to create tones, it is indispensable as a very important tones adjustment in the Sitar.
Furthermore most importantly, the tradition of which music transmitted by oral tradition is common to each other.
The musical instrument called Veena, which is said to have existed since BC in India, is also said to have the roots of Japanese biwa.