There are just so many things wrong with this film. For one, it exalts the male gaze, and every ostensibly "romantic" scene is simply a fulfillment of male fantasies.
The exhibition of teenage girls' underwear and legs even when it's absolutely irrelevant to the plot; the fact that this is then so often made relevant to the plot; the way two girls suddenly "become" lesbians and kiss juvenilely, bite tongues, suck on fingers; the male protagonist's unrealistically large erections that he cannot control, which female characters frequently discuss and sometimes touch; the forbidden stepsister fantasy; the farcical she's-in-love-with-me-but-doesn't-know-it-yet trope; the priest who's easily seduced just by having a crazy woman throw herself upon him; and not least when the film asks us to root for the protagonist to "save" his brainwashed love when he kidnaps her and attempts to show her how great of a guy he is for physically restraining her without molesting her. The film may centre around "the art of upskirt photography", and I have no problem with that in itself, but not once does it imply that this behaviour is ethically problematic, even when the victims are high school girls. I would say that this male perspective extends as well to the two-dimensional and implausible female characters—more than once, I wondered if this writer/director had ever spoken to a woman long enough to understand how they might think or feel—but the male characters also behaved in such an unrealistic manner that I'm starting to think it's more just a failure to understand humans in general.
Beyond that, the portrayal of mental illness, sexual orientation and fetishism, child abuse...they're caricatures of what these issues are really like, presented simplistically as plot points, but they're not even exaggerated enough to be satire. They're more like the stereotypical impressions one might have without having even experienced these things secondhand. And by that logic, this film only serves to reinforce such misassumptions, which is particularly problematic when one takes into account the likelihood that many Japanese viewers would not be able to recognise them as such.
And then there's the fact that characters frequently scream and flail about to express their feelings. Or react completely illogically to what others say or do. Or kill themselves or others (with melodramatic spurts of blood) for inexplicable reasons. Or have absolutely insufferable personalities—particularly the pseudo-mother Kaori, who somehow wins over the other characters by being tenaciously obnoxious. In short, this is possibly the least subtle film I have ever seen, along with the other Japanese film that feels like it was written by a middle-schooler: Kokuhaku.
Which is a shame, because there were a lot of themes to explore here: crises of faith, sexual deviance in society, gender identity, cult religions, nontraditional families, the lifelong scars of child abuse, and social ostracisation deriving from noncomformity, among others. In the end, however, each of these ideas were treated in the shallowest possible manner, and I can't say with certainty what statement the director was trying to make, or whether he simply hoped viewers would be drawn in by the four-hour plot and not notice the underdeveloped themes or characters.