If you liked the History's Strongest Disciple Kenichi manga, the Anime-Planet community thinks you'd like:
Minoru Kohinata has just become a student at Reinan University, a learning institute known for training Olympic-caliber athletes and martial artists – not for its academics. Having been kicked off the gymnastics team, Minoru’s only link to his former sport is his long-time friend Nana. But after trying to protect her from harm and being saved by the ruthless karate expert Ryuuji Mutou, Minoru finds himself quickly involved in the 2nd Karate Club, eager to finally become stronger.
Martial arts, good figthing scenes, same concept: "train harder, get better, fight stronger people".
if you liked Kenichi's story you would also like Karate Shoukoushi Kohinata Minoru couse both abord marcial arts from a funny and character developing point of view.
Karate Shoukoushi is more realistic and seing kenichi getting tortured by his masters is just priceless.
Isamu Take is a child genius who excels in everything he does. Forced by his parents to go to a regular elementary school, Isamu spends his time in boredom, looking down on his peers as nothing more than ungifted garbage; but when he meets Moka Kaname, his dull school life is set to change. The young girl, who has just transferred from Osaka, is a complete boxing nut, a trait that Isamu immediately finds vulgar. However, after an encounter with some delinquents, the arrogant boy discovers that not only is Moka incredibly strong, but she’s also smarter than he is! Now, having fallen in love with his new rival, Isamu needs to find a way to end more time with her, and he’s found the perfect thing: boxing.
While HSDK focuses on marital arts and Buyuden on boxing, both are about a beginner attempting to become stronger and more powerful. Both also feature a male protagonist whose abilities are far outstripped by the girl he has a crush on. If you enjoy either aspect in one of these manga, then check out the other.
The main guy protagonists start out as total wuss bags, unable to properly punch some guy in the face or kick his balls clean off. So they meet up with a bunch of hot chicks (Wilds) and a hot chick with another hot chick and manly flex men (Kenichi). But they learn about martial arts, how to defend themselves and even engage in some romantic tension while they're busy kicking ass and when they aren't breaking faces. Kenichi focuses more on ecchi than Wilds but both provide solid martial arts action and some depth behind all the bone breaking moves and styles with some great bouts of comedy; fun reads for fans of the martial arts genre.
Both History's Strongest Disciple Kenichi and Green Boy are about a physically weak boy who gradually becomes stronger. In both of those series the male lead joins a dojo (in case of Green Boy a boxing club). It should be noted that the fact that a girl he likes is a member of said dojo is a big part of the reason for joining (in case of Green Boy it's the main reason for doing so). Green Boy is more on the serious side while History's Strongest Disciple Kenichi has less romance and some fanservice, nonetheless if you liked one, odds are you will like the other one as well.
Ippo Makunouchi is an average and overly-shy high school teenager. His mother runs a fish boat shop and he constantly has to help her with it, and thus has no friends. Constantly bullied because of this, Ippo wonders what it would be like to be strong. A chance encounter with Takamura Mamoru, an up and coming boxer in the Japanese ranks, leads to Ippo's revelation that he has an incredible punch. Takamura sees potential in Ippo, and brings him into Kamogawa Gym. Thus begins Ippo's journey to discover just what it's like to be a winner. With a fighting spirit, can Ippo eventually become a professional boxer?
Both are really long and well known Shounen series. Ippo and Kenichi both started as good for nothing losers. Though Kenichi is bothered by this more than Ippo, the similar origins led me to enjoy both characters. They also both have some pretty cool fighting scenes!