Many of you who have seen this movie are probably wondering "What the heck was it all about?" Well, here's the answer, taken from the Urusei Yatsura Mailing list, and written by Anthony Baranyi:
The story is about growing up and having one's values and belief's change. In particular, since Lum is an only child, it also has to do with her learning that she isn't the "center of the universe". In the beginning of the film, Lum is the center of all the attention - the school film is being made around her, Lum is jogging and unbeknownst to her she is being tracked by the Mendo corporate spy network and so on. (This is typical of the storyline in most of the UY movies.) Then things begin to change. The issue is not just the loss of Lum's powers (which is symbolic to her losing the absolute attention she usually recieves), but the way that Lum finds herself "alone in the crowd".
Here the really original scenes begin - Megane and the rest of the gang of four are attracted to real and "attainable" girls instead of the unattainable "dream girl" Lum. Mendo is out with Shinobu and "only has eyes for her". Lum wanders in the crowded stores indistinguishable from the rest of the shoppers, now "just another girl". In Mendo's dream Lum is a "phantom" - unknown and unknowable, enticing him in the corners of his mind away from his self-centered dream. Appropriatly, Mendo is shaken from his reverie by his sister.
The issue of growing up is brought up openly twice. One time is while Lum and Ataru are walking into school and she berates him by saying that they "are 17 now" , meaning that he should "grow up". The scene with Shinobu on the terrace of Mendo's estate is similar - Shinobu is wondering out loud about the meaning of life once the comfortable dreams and routines of childhood are left behind. I suspect that Lum and Shinobu are being used as the "spokespersons" for this because of the old theory that girls "mature" (mentally) faster than "boys".
Lum has to choose whether or not to "grow up" - the scene with the "circus" is taken straight from Frederico Fellini - characters, music and all. Fellini used the "circus" to symbolize his memories of youth and a number of his best films (La Dolce Vita, 8 1/2 etc.) deal with his loss of the "innocence of youth". Thus when Lum goes off into the underwater dreamstate, she is making the decision wheter or not to "grow up".
The "grown up" world in this UY film is shown to be ordinary (but still acceptable to all but Lum, as per the reactions of Ataru, Megane, Mendo, Shinobu, etc. - they are getting on with their lives). In Movie 3 also, Tomobiki turns "ordinary" when Lum is away. In both cases though, reality is only "ordinary" when it is compared to the childhood ("the good old days", "the Golden Age", etc.). Lum chooses to retain her "childishness" and the magic returns to Tomobiki (in a very similar way to the ending of Labyrinth in which the heroine chooses to not yet release her childhood fantasies).
General Note: This film was made after the end of the TV series. As of the time of this writing (October, 1993), we have only released about 20% of the series, so some of the characters (such as Ton) have not yet appeared.
Lum's reaction to Ataru feeding her the umeboshi (pickled plum) at Mendou's Cherry-blossom viewing (hanami) party, i.e., "What did you feed me?!" stems from Oni getting drunk on umeboshi. For more details, see TV Set 11, Episode 42, Story 65, "Drunkard's Boogie." To find out about hanami, see "I Howl at the Moon" (Tsuki ni Hoeru), in OVA Set 2.
If you've ever seen a live crab taken out of water, it starts foaming. That's the reference Megane makes when he says, "H...Hey, Mendou! Is your cherry tree a crab monster or something?!"
Oshiruko is basically a soup made of sweet red beans. It's really sweet (essentially made with beans, sugar, and a pinch of salt), and resembles chocolate. It is also very high in calories, which is why Shinobu gives Ataru the line, "Too bad... I'm on a diet!"
As for Ataru's follow-up, "Then I'll rub your shoulders for you!" Parents (especially mothers) usually ask their children to rub their shoulders after a meal.
When the class shouts, "ULTRA SUPER ELECTRIC ATTACK!" the pose Lum strikes is from the legendary "Ultra Seven," celebrating its 25th anniversary as of this writing (1993), and considered the best of all of Tsuburaya Productions' Ultra Series. The pose is the mirror image of the one which Ultra Seven struck to fire his "Wide Shot," the most powerful of all his energy attacks: Ultra Seven shot from his right forearm, with his right elbow on the backs of the fingers of his left hand, whereas Lum fires from her left forearm, with her left elbow on the backs of the fingers of her right hand. She strikes the pose correctly a couple of times in the manga as well.
Cicadas come out in summer, dragonflies in autumn. The movie takes place in spring (April), hence the confusion.
"Oni no Kakuran" (lit. ONI's summer sickness) is an expression used whenever someone who never gets ill (esp. someone who's very strong and athletic) somehow gets sick. Used in reference to Lum, a real Oni, it, produces a nice pun in the original Japanese.
The word "Olm," apparently a measurement of intelligence, was a was a made-up word in the original, and when we asked Kitty for a romanization, they gave us authorization to romanize it as we saw fit.
The names of Mendou Shutaro's dream brides, "Sakura, Shinobu, Akina, Kyooko, Momoko, Yuki, Keiko, etc..." are, except for the first two, the names of popular Japanese Pop/idol singers and other "talents" of the time.
"The mountain where we chased rabbits..." (Usagioishikano-yama) "The river where we fished for small crucian carp..." (Kobuna, tsurishi kano kawa...) are lyrics from "Furusato" (which in this context is perhaps best translated as "Home"), a famous traditional Japanese song.