It's nature vs. nurture when a nerd swaps bodies with the toughest guy in school! Kang Too-Jee and Woo Soo-Choi have swapped...their bodies! After becoming the subjects of a mad scientist's experiment with her latest invention - the quantum teleporter - their bodies are switched, leaving only their minds and spirits intact. Woo Soo-Choi, who was once a model student, must face the life of Kang Too-Jee, a teenage menace. Never having an enemy in his life, he now has to deal with the handful of Kang Too-Jee's list, but will his kinder, gentler demeanor ward off his rivals? Or will survival determine his future? Will he become the hardened fighter that matches his new exterior?

Magunochi Ippo is an ordinary high school student in Japan. Since he spends most of his time away from school helping his mother run the family business, he doesn't get to enjoy his younger years like most teenagers. Always a target for bullying at school (the family fishing business grants him a distinct odor), Ippo's life is one of hardship. One of these after-school bullying sessions turns Ippo's life around for the better, as he is saved by a boxer named Takamura. He decides to follow in Takamura's footsteps and train to become a boxer, giving his life direction and purpose. Ippo's path to perfecting his pugilistic prowess is just beginning.

Kobayakawa Sena is a freshman in highschool. Despite his previous decisions to change his life, he finds himself in the exactly same place he was in during elementary school and junior high: a push over and an errand boy. However, this changes when Hiruma, the most feared person in his school and president of the American Football Club, notices Sena and forces him to join the Football Team. Now Sena will become Eyeshield 21, a mysterious running back with lighting fast speed.

Ryoma Echizen just joined the Seishun Academy's tennis team, which is known for being one of the most competitive teams in Japan. Its members are incredibly talented, gifted, and athletic. With rigorous and extremely intense practices, the upperclassmen of the team expect the very best from themselves and they expect even more from the new members of the team. While most of the freshmen are on pins and needles hoping they won't get cut from the team, Ryoma Echizen is confident, cool, and collected. Some might even say he's cocky, but at least he's got the skills to back up his attitude. With his virtually unreturnable "twist serve," Ryoma is sure to make the starting team.
Join Ryoma and the other first years, as they train hard, make friends, and try to find a place for themselves on the team. Ryoma Echizen is the Prince of Tennis. He may be ready for the Seishun Academy tennis team, but are THEY ready for HIM?

By the way, the Tennis skills in this series is completely beyond normal human standards and includes but is not limited to burning holes in your opponents rackets, striking your opponent so hard he flies several dozen meters, travelling in a spiral in mid air and even shutting down your opponents senses so that they cannot see, hear or feel (somehow) and therefore, has been put under the "Fantasy" genre.

NOTE: It has been announced that these 379 chapters serve as a prologue to a new series currently in the works. See "Shin Tennis no Oujisama" for continuation.

ANOTHER NOTE: Also, there is a short collection of 4 panel comics under the name of "Houkago no Oujisama", or "Prince of Afterschool" featuring characters and inside jokes from this manga.

From Miista MangaFox:

Bukiyou na Silent focuses on the dramatic love life of a teenage boy named Toono Satoru. Satoru has the longest crush he's ever had, on the school baseball player, Tamiya Keigo, who he watches from the art room window. One day, Satoru is asked to go on a date by Keiga, but all Satoru can do is stand there, emotionless, without saying a word. Little does Keiga know, is that deep inside Satoru, he is really shocked, amazed, surprised and literally speechless. Misunderstanding Satoru's impression, Keiga says to forget about it and tries to walk away, before Satoru grabs hold of him and accepts his request.

Throughout the relationship, complications, jealousy and an old friend, arise to make the two lovers situation problematic. As Keiga thinks that showing no emotion is hereditary in Satoru's family, he slowing begins to understand the feelings and emotions Satoru silently portrays.

From the author, Takanaga Hinako, perfectly portrays the notion of the teenage feeling of sexual tension, that will even have the reader understanding the emotions Satoru tries to convey. Read and discover whether the young boys conquer the challenge love awaits for them.

Japanese-American track-and-field star Mizuki has gotten herself to transfer to a high school in Japan...but not just any school! To be close to her idol, high jumper Izumi Sano, she's going to an all-guys' high school...and disguising herself as a boy! But as fate would have it, they're more than classmates...they're roommates! Now, Mizuki must keep her secret in the classroom, the locker room, and her own bedroom. And her classmates--and the school nurse--must cope with a new transfer student who may make them question their own orientation...

Hanamichi Sakuragi is a delinquent who has never had any luck with girls. However, when he meets Haruko Akagi, he is sure that she's the one for him. Haruko is a big basketball fan and notices his potential as a basketball player (due to his immense height). Hoping to win her heart, Hanamichi earnestly tries out for the basketball team. Does this complete newbie have what it takes to even join the team?

Japanese-American track-and-field star Mizuki has gotten herself to transfer to a high school in Japan...but not just any school! To be close to her idol, high jumper Izumi Sano, she's going to an all-guys' high school...and disguising herself as a boy! But as fate would have it, they're more than classmates...they're roommates! Now, Mizuki must keep her secret in the classroom, the locker room, and her own bedroom. And her classmates--and the school nurse--must cope with a new transfer student who may make them question their own orientation...

Teppei Sakamoto is a boy living in the countryside. He loves soccer, and all his soccer skills were taught to him by his sister. Finally, his sister wants him to join in Mizumoto High School soccer team. Teppei's turn in life has come!! How will this soccer newbie fare in the new environment?

Smash! is about two childhood friends (Shouta and Miwa) who share a common love for Badminton. Miwa, who\'s in love with Shouta, tries to persuade Shouta to apply to the same badminton school as her but the latter being of a carefree, easy-going and dense nature, brushes her away and states that he only plays badminton for fun.However, Shouta\'s perspective of badminton quickly changes after a fateful encounter with Yuuhi (a mute girl). In his search for his badminton goddess Yuuhi, Shouta met Anan and thereafter, decides that he\'s going to pursue badminton more seriously...

The purported advertisement from the Jump Square issue says that everything in The Prince of Tennis up to now has been "prologue" and that "a new legend for [the main character] Ryoma and the others will begin."

Silvermagic:

This continues what happened in the "Prince of Tennis ", after the end of the tournament . In "The New Prince of Tennis," Ryoma and the others (team members and teams they faced) begin a new adventure when they are the only 50 middle school students to be invited to the Japanese High School Representatives Selection Camp where only the top potentials in the Japanese tennis world train.What will happen now?

All that matters to 15-year-old Nobara Sumiyoshi is volleyball-she is an awesome player with big-time ambitions. But sometimes it seems like a girl just can not get a break in the competitive world of high school volleyball.Nobara s family wants her to inherit the role of "young mistress, serving rich patrons at her family s old-fashioned Japanese restaurant. No thanks! When Nobara transfers to Crimson Field High School, known for its top-notch volleyball team, it turns out that her mother will stoop to dirty tricks to keep her off the court. With assistance from her feisty Aunt Momoko, who is got some connections at Crimson Field, Nobara decides to start playing offense.

Maruo Eiitirou (E-Chan), a first year honor student, one day decides he is unhappy with the way things are and lacks excerise. He finds a flyer for the Tennis Club and decides check it out. He is instantly captivated by it. With no prior experience and poor physical conditioning, join E-Chan as he embarks on a tennis journey using his smarts, dedication and work ethic.

Pico and Mokkun enjoy a nice date at the amusement park, but Mokkun has ulterier motives.

[from Fantasy Shrine:]
Ritsuro is an expert in surfing and sex but a novice in love. As fate would have it, he meets another novice in both love and surfing. On the Shonan* beach, these two novices actually fell in love... with each other... But will their love survive from all the confusion, hurt, and growing up? A legend of love among surfers!
This book also collects one shot of a doctor and his patient!
(*Shonan: a leading resort area in central Japan famous for surfing, sailboating , and water sports)

Hiro has two loves: baseball and porn. But due to an elbow injury he gives up baseball choosing a school with no baseball team. His childhood friend Hikari attends a different school with baseball ace Hideo and the two wish Hiro had not given up baseball. Hiro joins the soccer team but meets Haruka, a very clumsy girl, who is manager of the unofficial baseball club. When the soccer team challenges the baseball club to a game, with hopes of humiliating them, the baseball club nearly loses until Hiro, disgusted by the soccer team's arrogance, switches to the baseball club.

Iseya Shou is the captain of the kendo club which is about to be shut down due to insufficient members. How far could he go to recruit additional members? Enters the charismatic student council president, Yagami Keishi. How does the manipulative strategist finally capture his guileless target?

Noritaka Sawamura is a teenager; until this day, everybody has been making fun of him. Now he enters the high school which is an opportunity for him to restart a new life! He loves a girl of his school, but he needs to be a little bit stronger to be recognized by everybody. So he joins the Thai boxing section. His entertainment is very special, due to his master who seems to be a little mad. Noritaka will make you laugh, for sure!

Note:
My favorite passage is when Sawamura spins through a window with a helmet, his trousers missing, with crap coming out of his ass, and everybody looking at him. He is the most ridiculous man in the world at this moment!

Akatsuki and his good friend Kiyoharu (called Kiyo-chan by Akatsuki) have been playing 'two player' basketball for quite sometime. Unfortunately, things started to change after they have joined in a very strong basketball team in their new school. Both of them were forced to separate into two groups: Kiyoharu was in the 'B' group and poor Akatsuki was put under 'F' group, which is known as the 'Failure' group. However, Akatsuki was not discouraged at all. He continues to train hard and always has a smile on his face. Will Akatsuki succeeded in his promise to Kiyoharu to become an official player? And what is blocking the path towards reaching his goal?

A boy named Chinmi is very infatuated with billiards. Problems arise when a new student body president, Olive, suddenly decided to cut the funding for his billiards club. Unhappy with that, Chinmi wants to convince Olive that his billiards club is worthy of the funding. He decided to challenge a two-time former national billiards champion. Will Chinmi be able to defend his club?

Akane Tachibana is a freshman high school student who, despite his talent for basketball, decides to abandon sports clubs due to the pressure put on him by them. Once he arrives at Kouzu High, however, he meets the only other basketball player who has ever caught his eye on the courts and decides to join the team. The first match of the season is an exhibition game against the league's strongest team, Hyamazaki—the team that Hiiragi's father coaches and in which his older brother plays for. Hiiragi ends up playing in the second half of the game, and they seem to not be working well together on the court, losing the game, until unintentionally one of the senior players on the team challenges them to beat him. They join forces, inspiring the team to victory. Thus starts the story of a group of teenagers working to reach the top, fighting tooth and nail the entire way.

Believing himself to be useless at football, Aizawa Kakeru opts to become the manager of his school's football team, while his brother Suguru is its ace, and is even good enough to represent Japan. However, Kakeru may be harbouring a strong talent within himself that only Suguru can see, and the two often get into arguments over Kakeru's denial of his skills. Things are made more complicated with the return of Seven, an old playmate of theirs that Kakeru has a crush on. Join the brothers in their journey to the national and even international championships!

Japan, 1995. After graduating from high school, Itō Kaiji moves to Tokyo to get a job, but he fails to find steady employment because the country is mired in its first recession since World War II. Depressed, he festers in his apartment, biding the time with cheap pranks, gambles, liquor and cigarettes. Kaiji is always thinking about money and his perpetual poverty frequently brings him to tears.

Kaiji's unrelenting misery continues for two years until he is paid an unexpected visit from a man named Endō, who wants to collect an outstanding debt owed to him in Kaiji's name. Endō gives Kaiji two options - either spend ten years to repay this outstanding debt, or board the gambling ship Espoir ("hope" in French) for one night to clear the debt. Using a con, Endō pressures Kaiji into accepting the deal, believing he will never come back from the voyage.
--Wikipedia

The manga is divided into three parts:
Part 1: Volume 1-13 (Complete)
Part 2: Volume 14-26 (Complete)
Part 3: Volume 27-39 (Complete)
Part 4: Volume 40-? (Ongoing)

New Series by Hiroki Endo, about a young man training in Shooto style MMA.

The private school, Cross School that Ryoko attends, is a special school that has an art faculty. However, Ryoko does not have any interest in people from the art faculty! Unlucky for her, the well known [Prince of the Art Faculty], Sei, stole her first kiss <33 Furthermore Sei keeps clinging to her without a reason, causing her to get excited. But Sei is younger than her, has a huge ego, and is super perverted! Oh my gosh~!! Ryoko, what is gonna happen now!?!?

All the girls are crazy over the swimming prodigy Wakatsuki Ran, but all he seems to be interested in is swimming.
One day, Ageha, a girl who wants to find love, but isn’t really looking that hard, bumps into Wakatsuki Ran. She instantly pegs him as a "stupid, obsessed swimmer" and does not take him seriously.
However, after she recognizes his talent, she is amazed and does something everyone least expects, she asks him to teach her to swim like him.
Except, is that the only thing she wants of him, or is it that she likes him? Moreover, how will their relationship develop and will he reject her if she does like him?

Hana Suzuki loves only two things in life: eating and sleeping. So when handsome senior Izumi Oda asks Hana–his major crush–to join the school hockey club, persuading her proves to be a difficult task. True, the Grand Hockey Club is full of boys–and all the boys are super-cute–but given a choice, Hana prefers a sizzling steak to a hot date.

Then Izumi mentions the field trips to fancy resorts. Now Hana can’t wait for the first away game, with its promise of delicious food and luxurious linens. Of course there’s also the getting up early, working hard, and playing well with others. How will Hana survive?

Kuroko is a member from the legendary middle school basketball team known as "The Generation of Miracles ", and while nobody seems to know about him, the main 5 players of the team all admit that he is a better player. When he joins the high school basketball team, everyone is surprised to find out that he is small, weak, and easy to miss. What is the secret that makes him so strong, and how will he help his high school team?

-Nins Leprechaun