“Shōgun” is the kind of Hollywood product that assumes a defensive crouch from the outset. The FX series—a ten-part adaptation of James Clavell’s best-selling 1975 doorstopper, which centers on an English sailor who lands in seventeenth-century Japan and rises through its samurai ranks—was announced six years ago with reassurances from John Landgraf, the network’s chairman, that this version would be au courant with modern sensibilities. “It’s not an easy thing to get right,” Landgraf admitted, adding that the show’s creative team would consult experts in “feudal Japanese culture” and feature a cast of “almost entirely Japanese actors.” (A previous miniseries, from 1980, hadn’t bothered to subtitle the Japanese dialogue: producers felt that if the British protagonist, John Blackthorne, couldn’t comprehend what was being said then neither should American audiences.) These production details were intended to distinguish “Shōgun” from the many Western films and TV shows that have been made under the assumption that, while Asian aesthetics are worthy as spectacle, Asian people do not merit understanding, identification, or individuation—or, in the most egregious cases, any presence at all.

The series opens with Blackthorne (Cosmo Jarvis), but, to the credit of its husband-and-wife creators, Justin Marks and Rachel Kondo, “Shōgun” doesn’t confine itself to his point of view for long. A proud Protestant, Blackthorne has been searching for a route to “the Japans” to catch up with the Portuguese, who arrived there in the name of gold, God, and glory a half century earlier and have kept its location a secret from other European nations. After Blackthorne and his men wash up on the shore of a small fishing village, his ship—with its many cannons and muskets—is claimed by Lord Toranaga (Hiroyuki Sanada), who sees the “Christian weapons” as the advantage he’ll need in an impending conflict with his rivals. Five regents, including Toranaga, have been entrusted to maintain peace while keeping the royal seat warm for their deceased sovereign’s sole heir, who has yet to come of age. But, by the time the series begins, Toranaga’s quiet consolidation of power has so threatened the other four that they’ve aligned themselves against him. The dreams of the dead can seldom compete with the ambitions of the living.

Early on, a fellow-sailor informs Blackthorne of a Japanese belief that “every man has three hearts: one in his mouth, for the world to know; one in his chest, just for his friends; and a secret heart buried deep where no one can find it.” Toranaga embodies this spirit of hidden ambition. He employs Lady Mariko (Anna Sawai), a Catholic convert fluent in Portuguese, as a translator for the polyglot Blackthorne. Like Toranaga, she prizes discretion; she tells her new charge that her people are taught to compartmentalize their feelings, erecting “an impenetrable wall behind which we can retreat whenever we need.” But characters defined by their opacity tend not to make for dynamic scenes—hence the dramatic (and comedic) value of Blackthorne, a brute who refuses to bathe more than twice a week, still believes in medicinal bloodletting, and addresses a local lord as a “milk-dribbling fuck smear.” Unlike most of his Japanese counterparts, he voices his wants constantly: to reunite with his few surviving crew members, to pursue the married Mariko, and, in time, to advocate for the commoners whom he once dismissed as “a savage horde.”

The show’s world-building is elaborate and sometimes hard to keep up with, but it may also feel familiar. Studios and streamers have been trying to create the next “Game of Thrones” for at least a decade, investing heavily in fantasy tales, medieval realms, and pricey I.P. HBO attempted to build on its initial success with a Targaryen spinoff, “House of the Dragon”; Amazon spent hundreds of millions of dollars on a “Lord of the Rings” prequel series it hoped would inspire similar devotion. In the case of “Shōgun,” a “Game of Thrones”-style premise is accompanied by “Game of Thrones”-style carnage: in the first episode alone, there’s a surprise beheading, death by boiling, ritual infanticide, and off-screen seppuku. (Many other hara-kiris will take place in plain view before the season is over.) Blackthorne, whose time at sea has made him no stranger to violence, finds the routine slaughter appalling. Toranaga, too, is reluctant to enforce honor codes that end not just single lives but entire family lines—and wary of the possibility of a new shogunate, deeming such a military dictatorship “a brutal relic from a bygone era.” This restraint is undercut by one of his generals, the cocky Yabushige (Tadanobu Asano), who, despite his sadism as an executioner, comes across as the series’ most believable character for his blithe self-interest and transparent scheming. The general’s slippery desperation as he attempts to play both sides, heightened by Asano’s petty-uncle energy, yields one of the season’s most engaging story lines.

Like “Game of Thrones,” “Shōgun” is a demanding watch, with dozens of characters sharing long, interlocking histories; a sprawling in-universe map; and frustratingly dim cinematography. By my count, about three-quarters of the dialogue is in Japanese, and it’s something of a wonder that the show exists at all, with a cast unknown to most Americans and a setting so far removed from us by time, geography, and culture. That distance is attenuated through gobs of exposition, and with weighty, often inelegant monologues that reinforce (and fail to enliven) well-worn themes. But Marks and Kondo also know how to highlight the show’s distinctive assets. The action, especially on the water, is impressive, and the sets and costumes are lavish. A slight lens warp lends the scenes at court a sense of grandeur. And, though much of the season is dour in tone, some of its best twists are the product of a dark wit.

Even so, “Shōgun” ultimately feels more like a curio than like a compelling series. “Game of Thrones” excelled at the macro—who’ll prevail, and how?—and at the micro, which made the interpersonal ties among its characters relatable, or at least recognizable. “Shōgun” struggles on both fronts. Toranaga’s rivals are scarcely differentiated, making it difficult to truly grasp what one regent’s rule versus another’s would mean. And, despite the series’ emphasis on lineage—Mariko suffers unduly for her bloodline, which has been tarnished by her beloved father—the parent-child relationships that were so central to “Thrones” are nearly absent here. Mariko gets a few warm exchanges with her growing son, but she seems perfectly content to leave him behind, fantasizing about killing herself in order to be reunited with dead relatives. Matters of protocol and duty eclipse all else.

Blackthorne’s gradual understanding of such samurai mores is meant to mirror our own, but his demotion from the novel’s lone protagonist to one of several leads gives audiences little to seize on emotionally. His journey toward “enlightenment” and his unconvincing affair with Mariko are thinly sketched—and, because “Shōgun” is at pains to foreground the regents’ war, he has more to offer the narrative as a source of discord and of new martial technology than as a romantic hero.

In theory, elevating Mariko and Toranaga to primary characters is the “correct” update, helping to avoid another “whitewashed” tale about Japan. But both are so bound by repression and secrecy that they’re almost doomed to be dramatically inert. Though the marvellous Sanada exudes an enigmatic nobility, Toranaga’s refusal to confide in his advisers thwarts any real insight into—or investment in—his ascent. Blackthorne gleans some wisdom from his time in Mariko and Toranaga’s company, but he still frequently misreads the pair, presuming desires they haven’t voiced and may not possess; when they decline to clarify their true feelings, the viewer suffers, too. The show’s own heart is buried too deep for us to hear it beat. ♦