Nearly every Yellow Man Group performance begins the same way: the four members storm the stage in blazing yellow outfits, excitedly introduce themselves with a highly choreographed dance routine, and proceed to take photographs of one another and the audience in candid poses. It's a rare case in which repetition does not breed tedium; this manic opening sequence is so stylish and exuberant that it never gets old. But though the Tokyo-based troupe's style can be kitschy, the performers are rock solid when it comes to improv fundamentals: classically trained actors, stand-up comics, and dancers, they learned their craft from deep thinker Keith Johnstone, and his seminal book Impro is their bible. Although the players' command of the language is somewhat limited--all are native Japanese speakers--they perform entirely in English, and their imagination is limitless: the suggestion of "to be or not to be" at last year's Chicago Improv Festival sparked a brilliant postmodern reinterpretation of Hamlet before veering off into even stranger territory. It's easy to see why Yellow Man Group has been one of the biggest crowd pleasers at the last two festivals: its players have a true flair for physical comedy and mime, and their good-natured, pure-hearted approach is infectious. Yellow Man Group kicks off a bill with Mission Improvable and all-stars Schadenfreude on Friday, April 5, at 10:30 PM at the Athenaeum Theatre, main stage, 312-902-1500. $25. A midnight jam session with Chicago's Stir-Friday Night! follows at WNEP Theater. $5. General festival information: 773-862-5082.