Like below posters and some people elsewhere have said, it's comparable to One Piece. Adventurers having ability fights, regions where government authority doesn't extend well and might makes right, a protagonist who is dumb and good-natured yet capable of righteous anger, with unexpected endurance and power. In search of "Oz" rather than One Piece. However, with the 3 chapters currently out, the story's initial potential seems to have completely disappeared.
Spoiler: I'm about to vaguely describe those of the story's plot elements which are presented in chapter 1, and name a couple examples from chapters 2 and 3.
To sum up my opinion: I could imagine the author thinking, "What kind of manga should I write? I could have fun with a crazy world like One Piece. Make Luffy female... Have a father character who's disappeared a la HxH... Throw in yuri subtext and various elements from otaku culture... Some themes of loss and a cruel society that wishes for people to forsake their dreams, to make the readers feel and sympathize with the characters' plight..." And writing chapter 1 based on that, and then from chapter 2 onward just throwing in random stuff they encounter in their travels, not realizing that doing so is too lazy and something that isn't worthy of comparison to One Piece... The series is still fun to read, but not something I feel passion toward. Also takes itself a bit too unseriously at times (I can't feel plot tension toward an attack from a wild animal whose natural prey is "little girls that like bananas"...) And a country of maids, etc.
There may be persistent elements that appeal to you, and the first chapter is in some ways worth reading just for itself, but later chapters so far don't have as many different types of appeal as the first chapter.
By the way, I want to emphasize that many people are able to enjoy Banana no Nana for the humor and various quirky story/plot elements and characters (which are the persistent elements I just described), but others may be affected by what I described. (Readers should understand themselves and whether what I've described would be relevant to them.)