Amakuni Saruno is a 15 year old student of Junishi High School. As a teenage boy, he desperately tries to find a girlfriend. Being fed up with seeing all the girls fall in love with high school athletes, he decides to join a sports-club himself. He starts looking around at the different sports clubs with the guidance of his friend, Kengo Sawamatsu . They go to check out the weight lifting club (of which there is only one member, a large, frighteningly buff guy), only for Saruno to see a girl that he assumes to be the manager of the club and show off for her. After sufficiently hurting himself, he helps the girl, Nagi Torii, carry some weights off somewhere, and while talking to her finds out that she is actually a manager for the baseball club, not the weight lifting club. Saruno decides to join the baseball club so he can win Nagi's heart.

Basically, your average sports manga.

A manga run from 2001-2006, it's a wacky baseball manga full of gags and ToiletHumor.

!!''Mr Fullswing'' has examples of:

* AllThereInTheManual: Character profiles, extra infos and occasionally, a Q&A are provided at the end of every chapter.
* BookEnds: The first and final chapter starts with the very same scene. Saruno and Sawamatsu peeping the girls locker room with a recording device.
* BreakTheCutie: [[spoiler: The reason why Inukai and Tatsuragawa's friendship with Miyanagi broke off is because of the death of their mentor Ookami.]]
* ButtMonkey: Saruno. [[MeaningfulName Even his name -Saru- translates to monkey.]]
* CerebusSyndrome: While the humor is still intact to the very end, the main focus however was slowly transitioning from gags to the actual baseball.
* DemotedToExtra: Played for laughs to Sawamatsu and later, Nezu.
* FanDisservice: Akemi, Saruno's alterego.
* FanService: From time to time. Especially in earlier chapters.
* {{Foreshadow}}: Remember in the earlier chapters? Where Saruno has a fantasy of his romance with Nagi, it ended with them being divorce, and a few later chapters, he was pleading in his sleep to his dad to not beat him up? Well, it was all played for laughs [[spoiler: until in later chapters it was revealed that his parents are divorced, his father took his brother and trained him to be sociopath whilst Saruno had to help around his mother's job as much as he could]].
* GoodScarsEvilScars: Kuzikiri [[spoiler: and Ushio]].
* {{Kuudere}}: Inukai
* JerkJock: Averted with nearly everyone. However, played straight with [[spoiler: Yomi]].
* KnightOfCerebus: The whole team of Kabu, though arguably, it traces back to the first appearance of Shikame.
* LoserProtagonist: Saruno, though he gets better.
* MeaningfulName and ThemeNaming: The main team characters' name correspond to the Chinese Zodiac.
** The school itself is means Chinese Zodiac (Juunishi).
* OlderThanTheyLook: Tomaru, Inori and Shikame.
* ShoutOut: Several.
** There's a ''Anime/{{Doraemon}}'' shout out, where Sawamatsu becomes 'Sawamatsumon'.
** Shiba's apparently a fan of Music/{{Queen}}.
** There's a scene where Tomaru's playing a ''Manga/CaptainTsubasa'' game.
** One entire chapter parodies Tokyo Friend Park, a famous Japanese Gameshow at the time.
* ShrinkingViolet: Shiba, to the point nobody has heard him [[TheVoiceless speak even a word.]]
* SmallNameBigEgo: Subverted with Saruno. He does have the potential, but too much of the ego.
* ToiletHumor: Nearly every chapter.
* YoungerThanTheyLook: Mizo.