When Makoto enters the strange world of El Hazard, he finds himself struggling against his high school enemy Jinnai and other forces for the only weapon that can save this mysterious the living Ifurita. A Graphic Novel. Original.
A multi-person isekai fantasy adventure comedy. It's easy to follow (despite the terrible writing and huge plot gaps), and reminiscent of 90's adventure manga. It's okay.
Might have given it a 2.5, even a 3 maybe 10-15 years ago. However, I decided to judge it as a current and admittedly long-time reader of manga.
Without being bad, El-Hazard is really nothing special. At the time of its publication, harem science fantasy had not been codified as such, and people from one of the (if not THE) trope codifiers, Tenchi Muyou, were involved in this one as well. Furthermore, it is an unassuming Isekai ("Otherworld") manga, long before that was considered a genre (but by no means among the earliest).
So we have people from our world traveling to a science fantasy dimension, a win-all golden boy protagonist, a loser villain and lots of super powered girls,at least three of which fit the Maiden, Mother and Crone motif. In really simplistic fashion, all the otherworld characters are basically NPCs, submitting readily to the ambitions / heroics / prophecies and whatnot of the "real-worlders".
It is not bad per se, but nothing to waste too much thought on.