• Introduction
• Why is the title of the anime 'Project A-ko' ?
• What's with the asteroid?
• Why are the names of the characters "A-ko", "B-ko" and "C-ko"?
• Why are A-ko and C-ko wearing different uniforms?
• Is B-ko a lesbian?
• Is C-ko a lesbian?
• Is "D" a man?
• Why is B-ko dancing with those fans?
• Is A-ko's father Superman?
• What was B-ko watching at the very end of the movie?
• Are there any sequels?
• What's this about in-jokes in the movie 

Introduction

With contributions from: Derek Upham, Ken Arromdee, Jon Beckett, Enrique Conte, and Curtis H. Hoffmann. 

Why is the title of the anime Project A-ko ?

What's with the asteroid?

Why are the names of the characters "A-ko", "B-ko" and "C-ko"?

Another possible explanation is that the names describe their attributes. A-ko = Athletic, B-ko = Brainy, C-ko = Cute. (So what's D?) 

The use of letters could also emphasize the simplicity of the plot. A and C are friends. Here comes B, who wants to have C for herself, and tries to get A out of the way. Meanwhile, D is looking for a lost princess... 

The full names of the characters are "A-ko Megami", "B-ko Daitokuji" and "C-ko Kotobuki". 

Why are A-ko and C-ko wearing different uniforms from the rest of the girls?

Is B-ko a lesbian?

Originally, Project A-ko was intended to be another installment in the Cream Lemon series of adult anime. Sometime during pre-production, the decision was made to tone down the sexual situations and make a more mainstream anime film. It may very well be that B-ko was intended to be an overt lesbian in the original anime. (Given that the team who did Project A-ko was the same team who had just finished the acclaimed "Pop Chaser" installment of Cream Lemon, one has to wonder how the adult version would have turned out...) 

Is C-ko a lesbian?

C-ko has no interest whatsoever in sex. 
(Perhaps because the word is too long for her to understand...) 

Is "D" a man?

Why is B-ko dancing with those fans?

Is A-ko's father Superman?

"Dad" is reading the "Daily Planet", and the headlines are taken from the 1940's Superman cartoons by the Fleischer Brothers (which I heartily recommend). The one on the left is from "The Bulleteers", while the one on the right is from "The Mad Scientist". 

We meet B-ko's father in Project A-ko 2. Mr. Daitokuji has an uncanny resemblance to Tony Stark, a.k.a. Iron Man. This would explain the money (Stark is a rich industrialist), the powersuits (Iron Man's abilities come from his armor suit), and the rivalry (Marvel Comics publishes Iron Man, while arch-rival DC Comics publishes Superman). 

What was B-ko watching at the very end of the movie?

Are there any sequels?

What's this about in-jokes in the movie

• The alien captain has an uncanny resemblance to the moody protagonist of Leiji Matsumoto's CAPTAIN HARLOCK: SPACE PIRATE, who moodily fought against alien invaders. Harlock would be often seen moodily drinking a glass of red wine, so his Project A-ko counterpart was a drunkard.
• The alien ship itself looks like a cross between the Arcadia from CAPTAIN HARLOCK and the Yamato from Matsumoto's SPACE CRUISER YAMATO (a.k.a. STAR BLAZERS). 
• The space fighters from the Earth Defense satellite are taken straight from the old British SF series U.F.O., down to the way their missiles are loaded. In this scene, there's also an old-fashioned train-crossing signal with accompanying barrier. 
• The missile barrages with dozens of missiles twisting every which way are from the TV show SUPER DIMENSIONAL FORTRESS MACROSS, which first had that special effect. A famous double in-joke is that, in one of such scenes in the movie MACROSS: DO YOU REMEMBER LOVE (a re-telling of the show's story), some of the missiles are actually Budweiser cans and bottles of sake. In Project A-ko, the animators had fun with this by making a couple of the missiles into Pepsi cans (you can see them in the sequence with a fighter traveling down a long trench). 
• Talking about MACROSS, B-ko has the same cork-screw bangs as Linn Minmei, one of the female leads from said show. 
• C-ko is the epitome of the anime cliché of "the cute girl that can't cook." C-ko is mind-bogglingly cute, and her lunches are deadly even to her. Freeze-frame the bento box lunches C-ko gives to A-ko; some of them contain bottle caps and stuff. 
• "Ms. Ayumi" is a copy of "Creamy Mami" the star of a very popular "magical girl" show from the early 80's. That's why C-ko makes the comment that Ayumi reminds her of a famous person -- she probably was a fan of the show! 
• In one of the city scenes, one of the alien spider-machines crashes through a poster of "Madoka" from the popular manga KIMAGURE ORANGE ROAD. (It is not an in-joke to the anime series, which was still a year in the future at the time this movie was made.) 
• B-ko's transforming mecha beautifully illustrates one important point about the dozens of giant transforming mecha featured in a number of anime shows -- where does the pilot go? 
• The movie A-ko and C-ko are watching is a spoof on HARMAGEDDON (a.k.a. GENMA TAISEN), a dark SF film by Katsuhiro Otomo. In the original, the protagonist is stalked by a psychic-hunting cyborg. In this version, he's stalked by... Colonel Sanders!! 
• Among the people in the theater, you can spot "Ten-chan", from the very popular SF comedy anime series URUSEI YATSURA. In one of the classroom scenes, you can see "Oyuki" from the same show, her hair now blonde instead of a very icy blue. The sequence with B-ko flying up the fortress to rescue C-ko is a copy of a similar sequence in the first URUSEI YATSURA movie. 
• C-ko's tiara in the "temple" is from Go Nagai's "Fandora".

But what *is* Fandora?? 
• Hokuto no Ken is a VERY violent post-apocalyptic martial-arts TV show and movie. It recounts the adventures of Kenshiro, master of the "Fist of the North Star" technique and Macho-Man-From-Hell. "Mari", one of B-ko's flunkies, seems to have Kenshiro's abilities (and looks). Many of her lines are straight from Hokuto No Ken. Her final attack is the notorious "Thousand-Fist Attack" from said TV show, which will gorily explode the opponent's internal organs 10 seconds after it's executed (thus her "You'll be dead in ten seconds!" line). 
• In Project A-ko 3, Yawara and Jingoro (the two Judo masters from the TV series, Yawara), can be seen as customers at the fast food place.