I agree, it’s a shame it’s not in English also.
Yamaha keyboards is huge in Asia and I’m sure he has his followers and he is happy with that.
I am making ‘song styles’ whenever I need a new song, I copy an intro from a midi file in my midi sequencer to add Into/Ending on to a suitable Yamaha style, I can do that in a couple of hours but making a style for scratch would take much longer, I wouldn’t have the time or the patience for that.
Pino