Betterman is a 1999 one volume manga adaptation of the anime with the same name, published in the same time frame as it was airing (last chapter appeared roughly 2 weeks after the anime end). The one who contributed with the story is the brain behind the show Yonetani Yoshitomo while the artist is not so well known in the industry having small projects here and there in the 2000s. The manga is not something special or something different or even an enhancement version of the overall plot of the anime, it's a fast paced episodic action story with mecha fights which will seem impossible tofollow if the reader didn't have prior knowledge from the show.
It simply adapts 6 stories in 6 chapters and calls it a day, it's more of a recap in manga form with lots of complicated information and technical details that'll bore anyone.

The ending is the same as in the anime, if anyone was curious about it and gives us a preview of the sequel manga so in the end this was a double promotion.

A great thing about it is the art, some will characterize it as the basic 90s visual look with the characters having big moe eyes and girls with suple bodies, I consider it very nice to look at and better than the anime though there is not much difference. The girls are beautiful and Hinoki shines in all panels, the mechas are as impressive as in the anime.

I don't recommend this manga, it's way too confusing and fast paced, the fights take 2-3 pages and too much stuff is shown in a short amount of time. The only way this could work is if someone randomly sees the designs and some cool 2 page spreads and they'll be curious about the anime, otherwise it's pointless. If you watched Betterman and want more, you can browse the chapters to look at the terrific art, sadly there is no ecchi fanservice if someone was curious, it's consistent with the anime's amount of sexiness.