Let’s go for something obscure, shall we? This mangaka has no Japanese wikipedia page, and nothing documented in English, as far as I can tell, and while I assume I’m reading the name correctly, I’m not 100% sure (Japanese can be like that). So, presupposing that I’m not mangling the reading, Ippei Sama was a pro comic creator in the late 1960s and early 1970s, and frequently got work printed in Shonen King. Sama’s work is tough to get a hold of nowadays, but at least one of the titles looks Kong-relevant: Silver King.
According to the one review I can find for this manga, it’s from around 1965 (i.e. kaiju boom time), but there’s not a whole lot of actual giant gorilla in it. However, it looks like it’s not Sama’s only kaiju output. There was also a manga titled Nezulla, with no relation to either the failed Daiei film or the much-later horror flick. Actually, it’s not clear why this monster is called “Nezulla” at all, since it doesn’t appear to be a mouse, but instead a space dragon.
So, that’s cool and all, but why bring it up in a King Kong retrospective? Take a look at the cover:
This manga also features “King Kong’s brother”, White Kong, who battles against Nezulla at the climax.
Both of these antique comics are obscure enough that I don’t see any current auctions running for copies, but based on the handful of archival ones (the images for Nezulla come from an ended auction on Mandarake) I’d expect them to run at around $100 each. While it’d be cool to see them reissued at some point, there’s the question of the Kong copyright, current copyright owners (which can often be a headache to track down), and how much interest there is in the market (the quantity of new manga on Japanese shelves every year is mind-boggling, so there’s usually not room for re-issues unless they know they’re evergreen titles). The moral is if you want to read these suckers, it’ll probably take a fair bit of digging.