I saw this movie in DVD release that came out 10 years after its initial theatrical release, so there is a lot of making-of stuff on the DVD that reveals some surprising things about the movie, e.g. almost all the actors were first-timers; it was a huge box office hit in Japan; the director put down his own work as substandard (much too hard on himself, in my opinion).
The story itself turns and twists on the fact that characters who seem strong--Tatsuro and Yoriko--are actually weaker than their younger friends--Shin-chan and Asami-- who turn out to be strongest when they are the most vulnerable. The name of the escort service the boys work for is Pinocchio, a sort of puppet palace/donkey island where it takes something special to become a real, live boy. Overcoming self deception is the biggest hurdle. I suppose it is meant to be Tatsuro's movie, but Shin-chan stole it from him, not with any sort of mugging, but largely because of the charm of the character. All of the performances were pitch perfect.
I didn't come away feeling quite as gloomy as our other commentator did, maybe because I recognize low-key Japanese upbeat-ness when I see it. I was charmed by all four of these kids, but definitely not in a manipulated Hollywood sort of way. They all seemed like the kids I teach: very real, very embattled, and very resilient.
I have a quibble with the subtitles. They were mostly pretty good, but since it's an older movie, we're stuck with them... no way of turning them off. However, there was an occasional omission of some dialog from the translation that I could see no reason for, and--if left in--would have actually enhanced the understanding. I think perhaps this was critical in the last scene, and could be the thing that led the other commentator to find it depressing, because he didn't catch this one little bit of dialog--when Tatsuro tells Shin-chan how much he actually got for posing and Shin-chan's response to it--that was actually quite sardonically funny.