Gundams playing baseball. More likely than you think.
We get to see Sei piloting his Build Strike Gundam in space, his dad then warning that his Gunpla isn't snapped properly. Cue the Build Strike Gundam's arm popping out and getting shot down by Zaku.
The moment when "Mr. Ral" is introduced and seems to be pretty much an exact copy of his original series namesake…and promptly destroys that image by getting a Luminescent Blush when he sees Sei's mother.
Reiji getting used to the Build Strike Gundam's controls in Episode 1 causes the Gunpla to do a funny dance, Sei gets pretty embarrassed.
Sei's reaction and face to when Reiji is staying at his house, appearing at his school, beating up a student council member, and fades into light are just PRICELESS.
Sei getting called on to answer a question in school while trying to design upgrades for the Build Strike.
Sei: "Uh... the answer is 2/3!" Teacher: "This is a literature class!"
Gonda being called a gorilla. Kondo Isao, you've got a partner now.
"Mr. Ral", once again, appears out of nowhere just to give commentary about gunpla battles. And China's reaction. Her disturbed and frightened expression at first is what sells it.
China: "Just who is this man?"
Tatsuya's flamenco-laced Leitmotif during Zaku Amazing's Curb-Stomp Battle over Build Strike is hilariously awesome yet funny at the same time.
The topper comes in the final scene of the episode, with the ridiculous face Sei makes when Reiji glows red and transports off into god-knows-where.
When Sei asks him about his origins, Reiji explains that he is the prince of Arian, a country on another planet, and found a jewel in the royal treasury that brought him to Earth. His tone and the crayon-drawing art style while he's talking give the impression of a young child telling a fairy tale. Sei, predictably, doesn't believe him for a moment.
Sei: "So you're a prince from another world?"
Reiji: "Yeah, you get it now?"
Sei: "I get that you're insane..."
The Zeon Bar. And the entire bar greeting with "Sieg Zeon!".
RB-79 Ball was introduced as the "Spherical Coffin". Reiji used it to trounces an entire group of veteran Gunpla battlers. And, that's really all that needs to be said.
Sei gushing over how awesome it is to meet a girl who's into Gundam, complete with sparkles... while Reiji looks on, slightly confused.
Mr. Ral again screwing up the image of his inspiration by gushing over Kirara at the tournament.
When Sei fights Kirara, in what may be a parody of a Warrior Therapist scene, he claims that despite her claims of disliking Gunpla, he can feel her enthusiasm through how well built her Gerbera Tetra is. Then she just admits she had her fans put it together for her in exchange for photos. Kirara pulls Alpha Bitch-ery the point you can't help but laugh at how perfectly she pulls an Ignored Aesop.
After Kirara is defeated, Sei hopes that maybe they can still be friends and she can start appreciating Gunpla legitimately. Reiji looks over and sees Kirara whining with Ocular Gushers while her fanboys try to comfort her, then turns back to Sei and says "Yeah, fat chance" with a wonderfully snide expression on his face.
Ricardo tries to hit on a woman, by offering her a Victory Gundam Gunpla, only for Reiji to crash the party. Even better, it was working until Reiji butted in. And then Ricardo admits that he built it to pick up chicks, and the woman quickly sours and leaves when nobody's looking, prompting a Big "Oh, Dios Mio!" from Ricardo.
Mao tries to do the same, except it's to pay the driver that gave him a lift to Tokyo, and China's father for the meal. The former worked, the latter, not so much.
And then it turns out the payment was in a way accepted. It's a bit funny in a way to see the Gunpla holding a miniature electric guitar. An electric guitar/beam rifle that is Extreme Gundam's canon signature armament. It's a long story.
Mao's introduction to Sei and China.
Mao: "My name is Mao Yasaka. I won the Japanese 5th Block of the Gunpla Battle Championship, and I want to become the best Gunpla builder in the world! Sei Iori, I've got hold of you at long last—"
Sei and China just walked off as if he is some kind of weirdo, only for Mao to repeat his introduction, but faster.
Then Sei's lampshading.
Sei: "Do you think I attract weird people?"
China: "Yeah, I think so..."
Rinko's squee reaction when her husband, Takeshi is respected by Mao's master.
Sei: I wonder what my dad did.
Mr. Ral, once again channeling his namesake and delivering his iconic line:
Mr. Ral: "This is no Best Mecha Collection, boy! No Best Mecha Collection!"
The entire fight and the scene with the buildup of Gundam X Maoh versus the Build Strike imagination fight. It ranges from the dramatic plastic bag tumbleweed, to the epic kung-fu stance, to the drawing of the gunplas, to Mao's cosplay of Garrod, and then the reveal that Reiji is the pilot, with him wearing Kira Yamato's pilot suit.
In the middle of the fight, we cut back to reality, where Sei and Mao are frozen in place and staring at each others' Gunpla with jaws agape. Rinko worries that something's wrong with them (but China realizes they're imagining the fight).
And how does it end? With Mr. Ral breaking into their imaginations and telling them this match-up is too cool to be played out just in their minds.
Sei spots his mom peeking into the compressor room where he is talking to China.
Sei's squee reaction returns when he is explaining the history of the Gundam Mk-II.
Being a Beach Episode, we have Reiji staring back and forth on Rinko and China's chest (Much to the chagrin of Sei and Mr. Ral), commenting to China that she needn't worry about her assets. The end result is predictable.
Mr. Ral: "Straight into the minefield!"
What sells it is Sei and Mr. Ral's reactions.
Mr. Ral sleeping in a sand coffin. Or rather, sand Gouf.
Before that, the final round of the regional, when Reiji's opponent basically have to jawdrop within the timespan of 10 seconds.
Reiji impatiently waiting for Sei to finish what will become the Star Build Strike, clinging to the window of the painting room like a gecko.
Everything about "Caro-Chan".
After the big challenge to China, Caro-chan leaves the playground walking towards a horse. Did she actually arrive on... no, that's way too weird even for this show... is it?
At the beginning of the show, Caroline goes on monologue to herself and rant about how China repeatedly humiliated her and how she'll win this year. Everyone around her stop walking and have a "what the hell is wrong with that girl" kinda look on their faces.
China can't fake a smile to save her life. But the second she gets a call from Sei's mom...
The training montage. Complete with Nibun no Ichi playing in the background.
The Nobel Gundam in Berserker mode getting shot down by the Bearguy-III in one shot.
Also, Sazaki showing up at the all-girls tournament for no reason other than to stand in the background attempting to look cool.
The result of Plavsky Particles reacting to cotton: an immobilizing substance.
Kirara reintroduces herself to Sei. But when Mao obliviously asks who she is, her leitmotif cuts right out, then starts up again when Sei explains, only to shut off again when Ricardo turns on the charm.
Anything to do with Ricardo once he gets some alcohol, really. From his dropping his usual charm in favor of enthusiastically fanboying about Mobile Suit Gundam: The 08th MS Team's Blu-Ray extras, to his acing his first tournament round while still having the hangover of the century.
Chairman Mashita acting like a child, rolling on the floor, crying out in pain after Meijin Kawaguchi held his arm a little too tight. He even requested his secretary to relieve his pain like one would do to a 5 year old child. And it's super effective!
Reiji X Aila. Take 3. This time involving shoving meatbuns into one other.
To clarify: As Reiji leaves the convenience store, someone throws a bag at him which he catches. It turns out to be Aila, who bought meat buns using the excess money Reiji gave her last episode to repay the one he took. Reiji says he doesn't want them because they're cold, but Aila says she didn't know when she'd run into him again and insists he take them because she doesn't want to be in his debt. They end up trying to shove the bag into each others' hands.
We start with Mr. Ral's "Love in the air" detector. Whenever he detects love in the air, he buttocks will start to itch, prompting him to scratch them. China and Reiji both asked if he's alright but Sei took it to another level, deducing it to be hemorrhoids.
The various "Original weapons", ranging from a normal tonfa or gun to Mao's spray gun and Fellini's heat scissors.
Cziommer, thinking Bigger Is Better, enters with a WaDom and ended up with a normal sized handgun, which due to the size of the WaDom, is smaller than a peashooter (and too tiny for the WaDom's fingers!). Fellini quickly dispatches him with his "Heat Scissors."
Cziommer: "You're using the scissors the wrong way!!"
The cake is taken by Sei and Reiji. They got a cap, a glove and several balls (that resemble the RB-79 Ball, at that), turning the Star Build Strike into a baseball pitcher, then a stadium rises around them, turning the match against Luang into a baseball match.
Build Strike wearing the baseball cap is already really silly... and then enters Abigorbine with the cap dangling from its antenna.
The first pitch ends up being a foul ball... which has enough force to escape the play field and blast Kirara's soda can out of her hand, nearly smacking two nearby fans and leaving her looking on in Color Failure mode.
Announcer: "Please watch out for foul balls."
Mashita's secretary's Villainous Breakdown when her scheme to get Sei and Reiji eliminated fails utterly.
Cziommer vs. Fellini, Round 3. Cziommer is waiting for Fellini in his custom Loto this time to hit him with missiles only to have Felini vaporize his Gunpla with one shot from his Meteor Hopper. This, ladies and gents, is why you don't stop in front of a Buster Rifle.
Chairman Mashita's Oh Crap! face when Reiji broke open his door.
Sei's "WTF?" expression when Ral tells him about the Gunpla Mafia.
Fellini hitting on a woman only to realize too late that it's actually Mihoshi (a.k.a Kirara); he only realizes when she holds her hair up in twin-tails and tries to play it off like he was teasing her.
Sei's dream of reuniting with his dad is so cheesy, it's hilarious. Gunpla Bon Odori dance? Sei and Takeshi floating into space?
Kirara interviewing Cziommer. Cziommer blatantly says on the screen that Fellini will suffer the most gruesome defeat and wonders what Kirara sees in him, only to get chewed out by Kirara.
Rinko fantasizing about the press interviewing her, with one of the reporters hitting on her. She then closes the shop and dashes off, IN HIGH HEEL SHOES.
Aila has an even more cute expression while eating that ice cream cone.
Sei forgets that he has a drink in his hand and spills it when he takes a bow to thank Mr. Ral.
Reiji meeting an eccentric old man (who is really Takeshi Iori, Sei's father) who is too enthusiastic when it comes to Gunpla. He then got reeled into building Gunpla under his instructions.
On that matter, Aila is stalking Reiji, and got jealous when she sees him with the old man.
She then got spotted and reeled into Gunpla building as well.
Your response should be "Sir! Yes, Sir!"
Reiji and Aila competing with each other in various process of Gunpla building.
Takeshi returns to the Iori Model Shop, only to find out that it's closed.
Complete with plastic tumbleweed, and Sazaki cycling by.
Takeshi: "Rinny, I love you!!"
Becomes even funnier when you realize he was probably expecting to get some. You know what I mean.
By the time the episode is finished, one will realize that the entire Iori family are Cloud Cuckoolanders.
Rinko wakes both Sei and Reiji up, telling them they're late for the tournament bracket release. Sei is seen running, half asleep, towards the stadium while ranting about how humanity will evolve into Newtypes that are able to stop time.
Mao and his master talk about their respective favourite female characters in the franchise. Mao's answer is Emma Sheen, while his master's is Murrue Ramius. Cue clip show of Gainaxing moments.
Mao shows up at the start of the episode, seemingly to be cheerful and help out Sei and Reiji... by the time he leaves, they both decide he was probably just there to brag about getting a date with Misaki.
Reiji: "What was that about?"
Sei: "M-Maybe he's cheering us up in his own way?"
Reiji: "I doubt that."
A date which ends in an Armor-Piercing Slap before it even actually started because Mao wanted to immediately plant a kiss on Misaki. Reiji puts it best, really:
Reiji: "It's your fault."
Sei, China, Reiji, and Aila. On a group date. That is all.
In a blink-and-miss-it moment, the Gundam Twitter. Particularly this line:
And the lampshading of how the Kampfer Amazing's Binders really shouldn't be able to carry so many weapons.
Every single interaction between Nils and Caroline.
Special mention goes to the scene where they have to rebuild their Gunpla in one minute. China is cheering on Sei who responds with a Crush Blush. When Caroline cheers on Nils, his face shows discomfort and he politely tells her to be quiet. Of course, there was the contrast between their cheers:
China: "Iori-kun, do your best!"
Caroline: "Nils, win for me!"
Meijin Kawaguchi's random comment during the Build Strike vs. Sengoku Astray fight:
Meijin: "He called it Sengoku, but it uses a Chinese Technique?"
Baker's epic face-fault when Nils loses.
Chairman Mashita throwing a tantrum over finding out Sei and Reiji have made it into the Top 4. Mid-way through, he notices that Miss Baker is missing, and runs out of the room searching for her. And then we cut to Baker, who is hiding under a desk.
Sei, Nils, Reiji, and Mao in the apartment room. Hilarity ensures one after the other.
It starts with Nils saying things that you would usually hear at a meditation session (keep a calm mind, breathe deeply), and we are shown that he is meditating... with Reiji. The purpose of this is to uncover the secrets of the Plavski Particle that is possibly within Reiji's memories by meditation. Reiji, being Reiji, falls asleep in less than 3 seconds, complete with giant snot bubble.
Nils uses hypnosis on Sei, thinking he has memories about the Plavsky Particles buried in his subconscious. Sei's reaction is... to to act out all (and yes, we mean ALL) 43 episodes of Mobile Suit Gundam from Amuro Ray's perspective. Sadly, most of it happens off-screen, but we do get to see him recreating the original Bright Slap scene◊. Now recall that, according to Nils, these are Sei's memories from age 3...
Also, throughout the Bright Slap scene, Sei's face is Art Shifted to resemble Yoshikazu Yazuhiko's character designs from the original series.
Mao gets dumped by Misaki. Again.
Kirara interviewing China, who winds up outing just how Gunpla-obsessed Sei is, even in school, on National Television. She quickly realizes how embarrassing this would be, both for him, and Rinko watching in the crowd.
And in a blink-and-you'll-miss-it moment, Sei's dad manages to get inside their house and slouch about while waiting for Rinny... all while leaving the living room in a complete mess.
The climax to the Aila vs. Reiji battle.
The highlights are Aila telling Reiji that she didn't want to fight Reiji because she would have won. Reiji is NOT amused.
The individual call-outs are worth mentioning. When Nine tries to ask what's going on by entering through her cockpit, she literally shoves him away, saying "I'm not listening to you anymore!". Then Nemesis' sponsor Josef contacts her via video window; Aila shouts "Shove it, you geezer!", then tells his grandson "If you want to win a Gunpla Battle, do it yourself!", prompting the shocked boy to stammer out "Y-yes, ma'am."
When Reiji calls for the RG System, Sei is still WTFing over what just happened and just says "Y-yes, sir."
Aila reminding Reiji that he promised she could come live at Sei's, as she had nowhere else to go after quitting her team. Between Sei and China, the former is left flailing hard by Reiji's antics. And Mao continues to lament everyone else having better luck with women than him.
Best Bit: Reiji is still sleeping in his pajamas, still unaware of the commotion.
Rinko crossing her arms while vetoing Alia living in Sei and Reiji's room. China, standing next to her, only has the tips of her fingers crossed.
A bit later, Reiji reveals to Aila his origins as the Crown Prince of Arian (see Episode 3). Aila's reaction? Laugh herself sick.
Reiji: "WHY DOESN'T ANYONE BELIEVE ME?!"
After learning of Aila's background, Rinko immediately offers her a place at the Iori household. This heartwarming scene apparently becomes simultaneously hysterical when Rinko notes the added incentive of staying at her house: being close to Reiji. Aila's subsequent reaction is priceless.◊
Baker assures Mashita that the Meijin will beat Sei and Reiji, leading Mashita to actually display some Genre Savvy by pointing that all of Baker's previous plans had failed, leading to Baker's mini-breakdown.
Cziommer returns again, only to get crub-stomped by random kids, including Alfred Izuruha.
Takeshi finally realized that Rinko came to cheer for their son and wondered why he didn't know. Cue a Char-cameo sitting next to him calling him a spoiled kid.
Especially notable for those who saw the original Mobile Suit Gundam in Japanese, because not-Char's comment is the exact same Char says during Gihren's famous speech when Gihren asks the audience why Garma had to die.
The newtype sound-effect that came right before he said that helped.
The match between Fellini and Kirara, in which Fellini shows just how whipped he is when it comes to her. Luang, Cziommer and Greco becoming just as disillusioned as Sei and Mao is the icing on the cake.
And in a meta sense, Masami Obari remarked on Twitter that even though it's just a Gunpla, he now has to live with the fact that he gave a mobile suitLuminescent Blush for the rest of his life. Note the man is not worried that he just had one mobile suit molesting another, just that he made the victim blush.
Mao's Master leering at Rinko in a perverted manner, and then Ral suddenly butting in to protect her.
Not a funny episode by any stretch of the imagination, there is nonetheless a pair of quick shots after Sei and Reiji defeat the Exia Dark Matter. First, Mashita and Baker's Oh Crap! faces. Second, Allan, Nine, and a bunch of Mooks all fighting over the remote to the Embody System, only to be frozen in the most ridiculous pose possible to look at the TV as Sei and Reiji's victory is announced.
A Baoa Qu breaking through the roof of the stadium before a crowd of awe-struck tournament goers was pretty funny.
Who was Baker before she met Mashita? A Sayla cosplayer!
Ral and Chinan appear with their Gunpla, leaving Mao and Felini in awe of their...awesome. Kirara is more deadpan.
Kirara: "They're...absurdly strong..."
Fellini: "That's the true strength of the Blue Giant!"
Mao: "Master! You're too awesome!"
Having just watched Chairman Mashita and Baker disappear back to Arian, Sei puts two-and-two together, and assumes the same thing will happen to Reiji. He turns around to see him... absolutely fine. Though his fears were correct in the end.
Reiji being forced to return to Arian. However, much to his surprise, he finds out that Aila decided to tag along with him.
A long-awaited Lampshade Hanging when Tatsuya builds a Nu Gundam without the funnels installed, claiming they "are being tested at Anaheim". Turns out simply learning to use the things has its own drawbacks, as they're shown flying off without him.