Fūun Kabuki Den is a gaiden, a side-story. It essentially uses the same engine as Manjimaru (minus the zoomed-in view in the dungeons), but the tone is more slapstick than epic, owing a lot to the Kabuki theater which is full of colours and comical situations. It's much shorter than Tengai 2 as well, and there are too many battles to my liking, but the PSG and CD tunes by Kōhei Tanaka are excellent and this is still one of the greatest RPGs ever IMO.
Kabuki Den is actually a Final Fantasy(IV)-style TM/FEOE(slower pace, battles, over & underworld walking, 4 fiends, etc...). By RPG standards, its still
long.There are still regions that you tend to clear one at a time, but they're jam packed with questing instead of the stretched out run-through gameplay of Maru II.
Maru does take a lot of time to clear if you're playing it without guidance. But I blazed through the sections I was familiar with the second time playing and got half way through in 2 or 3 days on the Gamecube version.
You can just turn on the Turbo switches and hold down the button to clear most battles(PCE version).
Kabuki Den has a pretty good debug mode, similar to Ys IV's, after you finish the game(press I at the 'The End" screen and reload).
I recently got a preview book for Kabuki Den that shows some of the early development on Tengai Makyo III:
HIMIKO It stars a young blonde haired girl who appears to be some sort of sorceress and her companion is a giant pig named Yamataku!
I also have a PC Engine mag that had the most amount of info on NAMIDA before it was cancelled. I translated most of it with Photoshop and was going to post them on my long-dead TM site(I've got the images on a CD around here somewhere...).
The hero was a very plain looking boy who was orphaned and the only thing left by his parents was a necklace and he was raised by fisherman. There was a tall shady looking guy, a young blonde girl(Himiko?) who looked like Kinu and a white Dog named "Dog".
The game finally released for PS2 is radically different, but it looks like Namida's back story is similar.