I don't really know how to rate this, since I can't tell if the story was meant to be serious at all or if it was just an entire joke.
It was funny in some places, but the majority of it was just a bit too out there for me. So basically Jungle King is like the majority of yaoi on the market, with everyone magically being gay & wanting to bone every hot guy in the series. The story isn't realistic in the slightest, and has things like the main character randomly masturbating under a tree on a rescue mission in some jungle in Africa. There are about a handful of rape scenes, the majority of them being out in the wild jungle. There is some old geezer in the story who seems to be madly in love with the main character & continuously stalks him throughout the jungle, watching him have sex through his binoculars. Later in the story they go to some snowy area, where jungle dude is still reppin' his animal skin loincloth, with a huge mass of vines draped over his shoulder. Things just keep getting weirder, with a guy in a bear suit jacking off the poor main character, and random bear fighting rings that jungle dude got forced into competing. Jungle dude & the main character cannot stop having sex, even when they are trying to escape from the crazy people they are running from. The whole plot & line of events is just crazy weird. I found the side story hilarious though, and enjoyed that more than the main story.
The art is pretty good. I like her style. It is a bit weird in places though. The sex scenes were pretty detailed, if that is what makes you happy in life.
I didn't really like the characters. They weren't horrible, but they just didn't leave any overall impression & just blended in with the rest of stuff I've read. Like the story, I liked the characters in the side story better.
This was enjoyable to read in a sense since it was just so weird, but that was pretty much it. I wouldn't want to read it again or own it. I was mainly just chuckling at how hilariously weird/bad it was.
Overall I'd rate this a 6 I guess. Since while it was run of the mill characters, the weirdness made it unique. I wouldn't go as far as to say I liked it at all, but the art wasn't bad & at least I got a good chuckle.