Singular in spirit and execution, “Grosse Pointe Blank” is hip without being cute or cloying, and absurd in a uniquely satisfying fashion. Definitely for rarefied tastes, the film is an artistic triumph and a supreme marketing challenge. Making the material palatable for a general audience will require real promotional acumen, and one would like to believe that’s possible, considering the quality of the movie. However, it remains a commercial longshot, more apt to play a well-worn niche while confounding the masses. The surface story has a mundane, unthreatening quality. Martin Blank (John Cusack) is a young man in crisis who’s desperately in need of some breathing space to make sense of his life and his work. For the past decade he’s carved out a successful career as an independent assassin — one who works for the government. As the film opens, he’s completed a successful operation, albeit in a manner not endorsed by his client. His chief competitor and the bane of his existence, Mr. Grocer (Dan Aykroyd), wants him to become part of a “union,” and Blank is naturally weary about joining forces. He’d like to take some time off to consider his options but he has to do a “make-good.” The upcoming weekend also happens to be his 10-year high school reunion in Grosse Pointe, Mich., a posh suburb of Detroit where, coincidentally, he’s compelled to do the hit. Though he protests going back to his youthful haunt, it’s obvious a part of him believes coming to terms with the past is the only way he’ll be able to confront the future. The script, co-written by Cusack, effects a curious conceit. Though the protagonist could hardly be described as a typical working slob, his daily travails are otherwise as banal as anything to be found in a contempo romantic comedy. From a distance, it seems a tad precious, but the zeal and good nature of the cast overcome the artificial quality of the situations. The key to what went wrong with Blank’s life rests with Debi Newberry (Minnie Driver), the prom date he stood up. She’s now a disc jockey, and Martin collects his courage and walks into her control booth. For some reason his explanation that he “freaked out, joined the Army and became a hit man” is met with skepticism. Still, there’s considerable magnetic attraction between the two. Despite its offbeat trappings, “Grosse Pointe Blank” is foremost a romantic comedy. Its success derives from central characters who are accessible, likable and who we want to see get together in the face of considerable obstacles. The oddball and antic elements are secondary, and it’s a testament to everyone involved that murder and mayhem don’t slow down the ardor for a happy ending. Cusack is charming and assured in the film. There’s no question his character understands what he’s done and is capable of doing. But he’d like to move on. Driver’s Debi doesn’t want to let him off the hook so easily. Among the rogue’s gallery of vivid supporting players, Alan Arkin is a particular standout as Martin’s traumatized shrink who wasn’t let in on his client’s work until the fourth session and fears there’s no easy way to terminate their meetings. Also disarming is Joan Cusack as the generally level-headed person running the hit man’s office. Giddily directed by George Armitage — who’s been absent since the equally idiosyncratic “Miami Blues” in 1990 — the tone never falters, and that’s crucial. The filmmakers accentuate the pace with a jaunty music and song score and rat-a-tat editing from Brian Berdan. “Grosse Pointe Blank” definitely reinvents the boy-gets-girl-back convention with a vengeance, and those who survive this new assault emerge surprisingly stronger and happier.