This movie is thematically located in the aimless life of college kids in 1970-80s Tokyo in particular, but what it tries to challenge may have a wider resonance.
A country girl visits a college in Tokyo in search of her high school band heartthrob. In the course of finding him, she runs into various odd inhabitants of the college campus--a constantly horny coed, a psychology professor in search of the theory of shame, and of course her Mr. Yoshioka who still sings but has become an elusive campus nobody. Other students also come in and out, engaged in a rather bored campus life-- flirting, having sex, joining campus group activities, running around trying and pretending to revolutionize something(sort of like the movie itself), etc.
So basically this movie does not tell you a straight story, but it invites you to laugh (or grin) at so many moments with its rough but effective (read low- budget) visual and sound effects. Probably that invitation is not for everyone (as witnessed by the low rating it has got up to now), but it certainly made a very entertaining watch for me. Give it a try if you get a chance.