It’s only natural for them to be superheroes

“Fullmetal alchemist,” “Negima!” and “Hunter X Hunter” all center on young heroes with supernatural powers, but the differences in the style, tone and content of these manga reflect the vitality and diversity of Japanese graphic novels. Sales of manga in the U.S. and Canada skyrocketed from $55 million in 2002 to more than $125 million last year, according to the trade publication ICv2.

Americans unfamiliar with manga often dismiss them as flashy comic books, and some do contain elements that recall Carl Barks’ baroque adventures for Donald Duck and Uncle Scrooge, the never-ending battles that superheroes wage against the forces of evil or the high school high jinks of Archie Andrews. But in Japan, thousands of manga titles are published every week; they appeal to readers of all ages and encompass a vast array of genres and subjects. In the U.S., manga are rapidly becoming what “Nancy Drew,” “The Hardy Boys” and “Tintin” were to earlier generations.

Hiromu Arakawa’s “Fullmetal Alchemist” offers something that many American comics and animated films lack: heart. Young Alphonse and Edward Elric delved into forbidden knowledge when they tried to use alchemy to bring their mother back from the dead. They paid a terrible price for their transgression: Edward lost a leg and Alphonse nearly died; Edward then sacrificed his right arm to save his brother’s soul, which is preserved in a suit of armor (hence the series title).

The brothers’ picaresque adventures take place in a world that resembles late 19th century North America. While Edward performs his duties as a state alchemist, he and Alphonse search for the philosophers’ stone to restore them. The brothers free the inhabitants of a desert city from a charlatan posing as a priest, outwit a crooked functionary in a mountain town and rescue a trainload of passengers from hijackers. The sometimes violent action is balanced with broad comedy: Edward throws a tantrum whenever anyone comments on how short he is.

Neither the comedy nor the action detracts from the brotherly bond that forms the series’ emotional core. When Edward can’t save a little girl who’s been turned into a chimera, he thinks about quitting alchemy. As Edward broods in the rain, Alphonse reminds him, “I don’t even have a body that can feel the rain. It’s lonely inside here.... It’s hard.” Chastened, Edward resumes the journey.

Arakawa’s line drawings are clean and effective. She uses areas of black and halftone shadows to heighten a mood but never clutters the page with unnecessary details. Fans of the animated TV series, which debuted on the Cartoon Network in 2004, will find that the animators have followed her original designs very closely.

Ken Akamatsu scored a big hit in 1998 with “Love Hina,” which exemplified the “harem comedy”: A geeky guy is surrounded by beautiful girls who initially dislike him but come to love him. His new series, “Negima!,” continues the genre. Ten-year-old Welsh sorcerer Negi Springfield receives the improbable assignment of teaching English in an all-girl junior high in Japan. The girls initially refuse to respect him, then decide he’s cute. Most of the students have magical powers, and soon the class is casting spells, fighting vampires and subduing demons.

“Negima!” is an example of a “fan service” story: one that offers gratuitous cheesecake shots to titillate male readers. Panels are composed so the reader looks up the girls’ skirts, important discussions take place in the bathtub and various spells blow the girls’ clothes off. The maladroit romance between two college applicants in “Love Hina” has plenty of embarrassing moments but feels believable. However, a pack of nubile females pursuing a prepubescent boy may not play as well in the U.S., where some might consider these images slightly suggestive of child molestation.

In contrast to the clarity of the artwork in “Fullmetal Alchemist,” Akamatsu’s drawings overflow with fussy details that often make them hard to read. The 31 girls in Negi’s class look alike except for their hairdos, so the reader sometimes has trouble determining who’s saying what to whom.

Gon, the hero of Yoshihiro Togashi’s long-running “Hunter X Hunter” series, wants to follow in his father’s footsteps and become a protector of the world, or, hunter. To receive the license needed to pursue this demanding profession, he and hundreds of others must undergo a rigorous and often deadly program of training and tests. As he begins the qualifying exams, Gon makes three friends, whose complimentary skills help them overcome obstacles. Aspiring physician Leorio provides first aid; Kurapika analyzes situations and uncovers ruses; Killua is quietly deadly -- he comes from a family of assassins. What Gon lacks in size, he makes up in speed, agility and pluck.

With his spiky hair and outsize boots, Gon looks like the typical eager half pint who appears in so many manga. Togashi gives the character an added depth by playing his enthusiasm against serious reflections. Although Gon delights in the riskiest challenges, he also realizes that a hypothetical question in a test setting might pose an ethical dilemma in the real world. Gon’s moral sense gives him an appeal his relentlessly upbeat counterparts lack. Togashi’s artwork is cartoony in the best sense of the word. Gon and his friends move through a world that is appropriately bright and engaging.

In many ways, the challenges Edward, Alphonse, Negi and Gon face aren’t very different from the ones faced by characters in the “Harry Potter,” “Tintin” and “The Hardy Boys” series. There are still wrongs to be righted, mysteries to be solved, victims to be rescued and malefactors to be brought to justice. The stakes may be higher, the settings more exotic and the weapons more sophisticated, but the basic adventure continues. And the better manga offer a combination of words and pictures that speaks to younger readers looking for an alternative to the flashy visuals of video games, “Star Wars” and “Yu-Gi-Oh!” *