Writer-directors Jon Hurwitz and Hayden Schlossberg (2008's "Harold and Kumar Escape from Guantanamo Bay") may not have been the original creators of "American Pie"—that honor falls upon Adam Herz, executive-producing here—but their love of the series and empathetic respect for the characters is apparent during every second of "American Reunion." The fourth official installment in the franchise (let's not bother to acknowledge the other four direct-to-video cash-ins as canon) sees the exciting, more-than-welcome return of virtually every cast members from its first two entries, 1999's "American Pie" and 2001's "American Pie 2," as they slide surprisingly seamlessly back into their memorable roles. While there may have been some trepidation about being able to recapture the old magic of not only the big ensemble, but the delicate balance between raucous raunchy humor and identifiable sweetness, Hurwitz and Schlossberg prove to know exactly what they're doing. "American Reunion" is nearly as good as the teen classic original, only with the added benefit of nostalgic hindsight.

Their ten-year class reunion came and went without anyone putting it together, but it's better late than never as East Great Falls High's Class of 1999 reconvenes on their Michigan hometown for a thirteen-year get-together. Good guy Jim (Jason Biggs) and former band camper Michelle (Alyson Hannigan) have been married for nine years—a momentous event detailed in 2003's comparatively weaker "American Wedding"—and now have a toddler son. Heading back to stay with Jim's now-widowed dad Mr. Levenstein (Eugene Levy) for the long weekend, Jim and Michelle hope to spend some much-needed quality time together as they reignite their flagging sex lives. Almost immediately, Jim is also reunited with all of his old pals—mid-level sportscaster Oz (Chris Klein), married stay-at-home architect Kevin (Thomas Ian Nicholas), and motorcycle-riding world traveler Finch (Eddie Kaye Thomas)—and, inevitably, the forever crass Steven Stifler (Seann William Scott), secretly working as a lowly office temp. What begins for all of them as a chance to reclaim a piece of their former youths, however, gradually becomes a wake-up call that things will never be the same as they once were when they were seventeen.

"American Reunion" can be enjoyed by anyone with a taste for bawdy R-rated comedies stirred together with a helping of earnest sentiment, but it is a full-out love note to fans of the series who are intimately familiar with the ups and downs of Jim's coming-of-age and sexual history, from the botched coupling with foreign exchange student Nadia (Shannon Elizabeth) that was accidentally transmitted over the Internet, to his lascivious prom night with Michelle, to a super-gluing incident that wouldn't be wished on a person's worst enemy. Catching up with Jim—a likable if comically downtrodden protagonist—and the rest of the characters to see what they've been doing with their lives over the past decade-plus is nothing short of a treat by itself, so it's all the more special that Jon Hurwitz and Hayden Schlossberg have additionally taken the time to flesh out a deeper underlying story about the universal process into adulthood and the impossibility of living up to the feelings and memories of one's adolescent years.

For someone like me who had just graduated high school when the first "American Pie" was released and is the exact age as these on-screen people, the film rings true again and again. It's mighty deflating, for example, when Stifler throws one of his infamous house parties, only to discover guests who aren't so much pounding back vodka shots as they are sipping wine, nibbling on crackers, and putting more "age-appropriate" music on the stereo for the little ones they've dragged along. Or, how about witnessing what high schoolers are like in 2012 and no longer being able to recognize yourself in this new alien generation of teen? It happens to the best of us, and many of the laughs in scenes such as these are funny in their subtle, knowing bittersweetness. No matter how hard we may try, there's no going back. That is not to say the guys don't get into their fair share of trouble, particularly with Stifler at the helm. Their revenge on some snooty teenage guys is exactly what is to be expected, while the inadvertent compromising situations Jim gets into with his drunken, completely naked 18-year-old neighbor Kara (Ali Cobrin)—whom he used to baby-sit back in the day—are a hoot. His attempts to get her upstairs to bed as Stifler, Oz and Finch try to preoccupy her parents in the living room is one of many truly inspired set-pieces. Also priceless: Stifler's corruption of Jim's lonely dad, who tags along to the party and finds himself, as the trailers have already revealed, coming face to face with Stifler's mom (Jennifer Coolidge).

The "American Pie" series made names out of the whole cast, the lot of them seeing varying degrees of success in the ensuing years. With that said, everyone looks beyond thrilled at the opportunity to return and take another stab at these well-loved characters. With so much time passing, though, would they be able to reclaim their souls, their personalities, even their specific vocal inflections? Fortunately, the answer is a triumphant yes, with Seann William Scott (2010's "Cop Out") and Alyson Hannigan (2006's "Date Movie") especially impressive since their parts of Stifler and Michelle are so quirkily one-of-a-kind. Scott is an indomitable force, able to make an asshole somehow endearing, while Hannigan's relationship with Jason Biggs' (2008's "Over Her Dead Body") Jim is the beating heart of the picture. Answering once and for all that masturbation does still exist after marriage, Michelle and Jim nonetheless spot trouble up ahead and love each other enough to want to try and fix it. A late scene set at the reunion where they rekindle their feelings for each other while thinking back on the people they were when they first met is beautifully written and poignantly played. In regards to Jim, Biggs is fearless in going for a punchline, even if it means "hiding" his penis behind a clear pot lid.

Coming off his so-awful-it-just-might-be-brilliant performance in 2009's "Street Fighter: The Legend of Chun-Li," Chris Klein reconnects with the talented performer in himself that showed great promise going all the way back to 1999's "Election." Now a semi-famous guy better known for being on "Celebrity Dance-Off" than anything that landed him on the competition show, Oz has stayed true to himself, but perhaps not to the things he finds most important. His younger girlfriend Mia (Katrina Bowden) is still mighty immature, nowhere near the match for Oz that the gentle, intelligent Heather (Mena Suvari) was during their high school and college years. Now faced with each other again—Heather has brought along her cardiologist boyfriend Dr. Ron (Jay Harrington)—Oz is left wondering why he ever let her go. For Thomas Ian Nicholas' (2002's "The Rules of Attraction") Kevin, he is now a married man who adores his wife even as he silently resents the somewhat emasculated man he's become. When he sees high school sweetheart Vicky (Tara Reid) for the first time in probably over ten years, it's as if they never parted. Great friends again, Kevin and Vicky must navigate the feelings they still hold for one another and the fine line that they do not want to cross. As for Finch, tales of his eventful life make way for a few hidden truths destined to finally come to light as he falls for Selena (Dania Ramirez), a once-ugly duckling whom she remembers he was always nice to. Eddie Kaye Thomas (2008's "Nick and Norah's Infinite Playlist") is terrific as Finch, this time with an air of bad-boy charisma about him, while it's lovely to see the equally fresh-faced Mena Suvari (2005's "Rumor Has It...") and Tara Reid (2008's "Vipers") back in action on the big screen again. People seem to forget that once upon a time, Reid was a huge talent stealing scenes in films by everyone from Joel and Ethan Coen (1998's "The Big Lebowski") to Robert Altman (2000's "Dr. T and the Women"). Maybe being in "American Reunion" will give her the second chance she deserves.

Of all the returnees, Eugene Levy's (2009's "Taking Woodstock") turn as Jim's dad has been the most stagnant, a gimmick more than a fully-formed figure who shows up, tries to lend advice to his son, and ends up embarrassing him. Here, portraying a man who has lost the love of his life—yes, Jim's mom (Molly Cheek, seen in home movies) has passed away—Levy is more touching and more funny than he's been in the past, urged to get out there on the dating scene and live it up. His exploits at Stifler's party—and his scenes with Jennifer Coolidge (2009's "Gentlemen Broncos"), dynamite as always as Stifler's slinky, sultry mom—are a comic highlight of the film. It is true that we cannot always have everything, but there are a few missed opportunities on the way to the feel-good conclusion. First, Finch and Stifler's mom never come into contact—borderline-blasphemy for those following the series—and second, Shannon Elizabeth (2005's "Cursed"), as the sexy Nadia; Natasha Lyonne (2004's "Blade: Trinity"), as the worldly, advice-giving Jessica; and Chris Owen (2007's "The Mist"), as Chuck "The Sherminator" Sherman, are seen far too briefly in third-act cameos. Could the producers not have added an extra day to their shooting schedules to slightly beef up their screen time and roles? The reunion of the title also might have benefitted by stretching out a bit and culminating in a more lasting final image; in the annals of this cinematic setting, 1997's "Romy and Michele's High School Reunion" still reigns supreme.

A walk down memory lane as well as a hopeful look to the future (gotta love the jamming soundtrack of recognizable '90s hits with music from today), "American Reunion" is a winning comedy that knows the formula of this franchise, and knows just as well how to pull it off. Remaining true to everyone in front of the camera, writer-directors Jon Hurtwitz and Hayden Schlossberg envision where they all are thirteen years removed from high school, and they do it realistically and with an understandable hint of wistfulness. Thus, spirited off-color gags and high energy share time with human soul-searching as Stifler and the other guys learn a little something about the value of living in the present even if, deep down, they'll never forget the past. They shouldn't have to. "American Reunion" avoids feeling tacked-on by developing into a natural extension of a series of films that created a pop-cultural phenomenon, introduced new words into the vernacular ("MILF," anyone?), and re-introduced the ribald comedy genre for a whole new era. Its light but assured footprint on cinema's history should not be shortchanged, and "American Reunion" is a fitting capper to the one-of-a-kind coming-of-age saga.