MATT SMITH STUMBLES WHEN HE talks. His anecdotes sputter forward, swerve onto overpasses, then backtrack and gather speed. He talks so fast he almost outruns himself. In Helium, the show he's written and is performing at On the Boards, Smith uses his improvisatory style (he's a TheatreSports and Almost Live veteran) to relate his amorous experiences as a young man living in Japan. The style may be a matter of taste, but the show itself undeniably feels as though Smith is making it up as he goes along.

"For a moment, I think I understand World War II," Smith observes after a raucous night with some drunken Japanese men. It's a funny remark delivered off-handedly. Unfortunately, his reflections on the eccentricities of the culture and the allure of Japanese women are so fleeting that they don't add up to anything.

Director Bret Fetzer hasn't brought any shape to them, either. The only technique used to punch up a moment is to contrast Smith's frantic stammering by having... him... slow... down. The device wears thin, mostly because there's a random feeling about the placement of the silences, and the highlighted phrases often lack dramatic significance. What ultimately makes the piece such a disappointment, in fact, is an overall lack of purpose.

Certain episodes are amusing (the fate of Smith's testicles is always good for a laugh) and Smith is nothing if not open as a performer: He talks forthrightly about everything from an embarrassing venereal disease to the humiliation of a pre-operation pubic hair shave. What he doesn't do is reach any sort of epiphany. Smith could easily win converts telling his story at a party (which is what it feels like he's doing anyway), but he doesn't reveal why it's worthy of being shared onstage.

"I can have a conversation in Japanese if it's one on one and it's about me," Smith says humorously at one point. "Kind of like English now." He never reaches beyond occasional self-deprecation, however, to address that narcissism. The material is overflowing with pokes at the hubris behind Western myths and stereotypes but Smith never responds to any subtextual tug. After hearing about the third affair with a Japanese woman and his complete "bafflement" (a word that crops up several times) with the experience, I began to wonder if Smith was even aware there was anything more to address. Helium is too good-natured to be offensive, certainly, but it begs questions about intimacy and cultural differences that should be answered, not left floating.