History's Strongest Disciple Kenichi

• In the manga, Kenichi starts training at Ryōzanpaku after beating Daimonji. Miu's map was so confusing that Kenichi needed Honoka to decipher it for him.
• A short arc before Kenichi's showdown with Hermit showed that Akisame had brought Kenichi to train in the mountains to learn the art of tactics. In addition to learning such, Kenichi also showed that training can be a tactic in itself. This arc is not shown in the anime.
• In the manga, after the second battle between Kenichi and Hermit, there is a short arc where Kenichi and Sakaki challenged another dojo, where one of the members of the Shinpaku Alliance was learning an unsportsmanlike version of martial arts (poking the opponents' eyes, using foldable chairs to attack, etc.). This arc is not shown in the anime.
• Right after defeating Thor, the next chapter showed Kenichi slacking off in his training as he thought he was strong enough. His masters proved otherwise, with Apachai getting him severely injured. This is not shown in the anime.
• Right after the arc where Kisara quit Ragnarok, the following 5 chapters followed Hayato's recounts of his meeting with Apachai, and how he later followed him to Ryōzanpaku. This arc, which is not shown in the anime, was then immediately followed by Nījima's plan 'H' to get Hermit to join the Shinpaku Alliance. This is set after Kenichi went on the mountain retreat with Hayato in the anime, but in the manga, Kenichi participated in the action.
• There is a short arc where Kenichi's father visited him at the Ryōzanpaku Dojo, and after witnessing the actual training, tried to get Kenichi to return home. He brought along his new gun, rotowski, which he secretly brought without his wife's knowledge.
• Blood in the anime version is either significantly reduced, or removed entirely when compared to the manga.
• The anime ends before the YOMi arc(chapter 143 of manga), thus its existence is omitted. However, the YOMI was mention and their coming at the final episode. Also, in the OVA produced the members of YOMI were introduced as well as the existence of Yami, hinting at the possible return of the anime series.
• In the anime version episode 23 "Assault! The Next Door Ryōzanpaku!" where Izumi from Kenichi's gardening club visited Ryōzanpaku. Niijama noticed that Izumi has feelings of affection towards Kenichi after she asked if she and Kenichi can go home together, but got rejected because he already promised that he would go with Miu. Using Izumi to make Miu jealous, Niijima persuaded Izumi to go with him to watch Kenichi train, but this caused more trouble than expected. This story doesn't seem to have come from the manga version, but comes from Tatakae! Ryōzanpaku Shijō Saikyō no Deshi chapter 19.

The plot to the 5 volume monthly predecessor to the series was mostly the same, with a few major differences:

• Kenichi originally was part of the Judo club instead of the Karate club
• Shigure does not exist in the monthly version, and two of the masters are said to be away on a journey (the silhouette of one of them seems to be Shigure, however the other figure was rumored to be Saiga Furinji). Also, Akisame's age is said to be 28 instead of 38, but despite the 10 year age difference his looks are the same.
• Kenichi and Miu do not attend the same high school.
• Ma Sougetsu and Ikki Takeda both look completely different as the former has a much less muscular and intimidating appearance and the latter has short black hair. Additionally, Takeda is named Takenouchi (竹ノ内?) (possibly a parody of Ippo Makunouchi from Hajime no Ippo) and is the captain of the boxing team. Natsu Tanimoto is also instead named Natsu Sugimoto (杉本 夏 Sugimoto Natsu?).
• Kenichi appears to adapt a lot quicker to his martial arts training in this series indicating he has some natural talent in this version
• Nijima's hair is a lot shorter and more flat-bowl shaped.
• The group Kenichi battles against is named Snake (スネイク?) and is headed by three main members: Shōgo Furukawa (吉川 将吾 Furukawa Shōgo?) (Top One), Natsu Sugimoto/Hermit (Top Two), and Kisara Nanjō (Top Three). The three of them later appeared in Kenichi as members of Ragnarok (Furukawa appeared as Berserker). Ragnarok was used as the name of Snake's rival group.
• Kisara Nanjo's hair is different compared to the ongoing manga and anime and Shogo Furukawa was never shown chewing gum nor being normally passive compared to the ongoing manga.
• The original Hermit looked exactly (with some slight hair differences) like the new Takeda, still however clothed in the same Hermit outfit.
• Ryōzanpaku Master Differences: Shio Sakaki had a much slimmer build than in the spinoff, Apachai Hopachai was fashioned in the same clothes, with hair resembling Guile from Street Fighter, Shigure Kosaka is fashioned in more of a stereotypical ninja suit, Hayato is less muscular, Ma Kensei had the same outfit without his signature hat and a yin yang symbol on his shoulders, and Akisame Koetsuji had shorter hair.
• Ma Kensei and Ma Sogetsu are adopted brothers instead of real brothers.
• Kenichi did not mention his never-hit-a-girl policy.
• Instead of Ogata who saved Natsu when he was little it was Ma Sogetsu.
• It is a kind old grandpa who adopted Natsu and his sister instead of the other version of a heartless businessman.
• After Kenichi defeated Shōgo Furukawa (吉川 将吾 Furukawa Shōgo?) he became the Leader of Snake and become Top 1 reluctantly.
• Shōgo Furukawa (吉川 将吾 Furukawa Shōgo?) and Kisara become the newest disciple of Ryōzanpaku.
• Instead of Mycroft, Christopher Eclair fights Sakaki, but Mycroft makes a cameo appearance in a flashback of Sakaki burying him and Christopher in a desert and he is also mentioned briefly. In the fight between Sakaki and Mycroft (in the monthly manga), Sakaki also makes a reference to the burial. Though Mycroft's hatred for Sakaki is never mentioned in the weekly manga.