The Shadow Hero, by Gene Luen Yang and Sonny Liew (First Second, July 15, 2014, YA) is a graphic novel about a boy who becomes a superhero... Green Turtle, the first Asian American superhero!
During the Golden Age of superhero comics, the 1940s, the Green Turtle burst onto the scene to fight for China against the invading Japanese. Created by Chu Hing, a Chinese American cartoonist, it's probable he too was intended by his creator to be Chinese, though his face was never shown clearly enough to be certain. He didn't burst with any success--there are just five issues about his adventures, and there were no clues about his origins.
Now we have that backstory. In The Shadow Hero, Gene Luen Yang and Sonny Liew tell of how Hank, a boy born to Chinese immigrant parents becomes an unlikely and at first unwilling hero, pushed by his mother and assisted by the great Turtle Spirit of China. When his gentle shopkeeper father is killed by the Chinese mafia, Hank is determined to get revenge...and so the Green Turtle bursts onto the scene!
It's a story of much more than superhero adventures--it's historical fiction, as well, creating a vivid picture (lots of pictures, actually, cause of it being a graphic novel), of life in a Chinese community in California before WW II. And it's a coming of age story of the classic sort--a boy compelled to grow up and embrace challenges he never particularly wanted. And it's the sum of these parts, resulting in an exciting, sometimes funny, sometimes poignant story, with a lovely little twist right at the end that brings the themes of immigration and identity into zesty focus!
And as a bonus, there's an appendix in which the story of the original Green Turtle is thoughtfully explained, and the first issue of his adventures is reproduced (complete with an advertisement urging the "fellers" to send away for a ju-jitsu course...).
Short answer: Mind-broadening and entertaining, with an appealing hero and great artwork.
Note on age: it's very much YA in terms of theme, and there's the expected violence (distressing at times, though not gorey). So not one for the little kid running around in a cape, but more for readers of 12 and up, who might still have their capes but don't wear them in public anymore.