When each couple discovers that Piu-Piu is actually Alexander Piulitzer, an extremely gifted scientist who invented the Ark and discovered things like Time Travel and Immortality, they each have funny reactions.
—Zhamo comments on how he was always muttering a certain set of three numbers in the low 30s and high 20's, to which Eluca replies "...those are my measurements."
—Vahti comments on how someone once said that as humans evolve, their brains will get bigger and bigger while the rest of their bodies shrink, and how cute it is. Olgar remarks that it would be hard to wash hair in the future, to which Vahti replies that that must be why Olgar hadn't washed his hair in a several decades: to prepare for the future. Olgar sulks, saying that he just doesn't like it.
—Escher says that he's always had reliable instincts telling him what's safe to fight and what's not, and his instincts had been screaming at him to not mess with Piu-Piu.
When Olgar and Vahti talk to Piu-Piu for the first time, he makes rather open comments of how much he missed Vahti's bosom, and that he'd been thinking of Vahti's busy just before they arrived. Piu met Vahti and Olgar 10,000 years ago. He's that much of a perve.
—He asks Escher to try on, who says if Piu-Piu touches him, Escher would kill him. He then tells Musiea to give him her breastplate, to which she replied that she'd kill him if he touched her.
—He almost successfully brainwashes Ayuta into putting on the bikini. Ayuta, whose eyes have turned gold, repeats "Like a hood..." after Piu-Piu before Mana snaps him out of his trance. When asked for her breastplate, Mana and Piu-Piu go into a cycle of "Are you sure?"/"Yes I'm sure," "Are you very very sure?"/"Very very sure" before an exasperated Ayuta asks them to stop.
—Eluca offers her breastplate to Piu-Piu in exchange for his head, to which Piu-Piu actually had to ponder...
Whenever any character asks Piu-Piu about his two stand-up, paper mache girls on either side of him, he will tell them that they are not the girl's type because:
—For Escher, they don't like no narcisstic guys dressed up in all black.
—For Ayuta, they don't like guys who wear shorts like 12 year olds and look younger than they are.
—For Zhamo, they don't like little muscle-men and who will probably go home to drink protein.
—For Olgar, they don't like old guys, or old guys who are married to younger women.
—For Vieg in the prequel, they don't like guys who wear a scarf as if it were cold, yet go shirtless as if it were hot.
For Zhamo's particular one: "But I don't...hey, what's prot-"
In his defense, Vieg sputters that his scarf shades his neck from the sun.
Finding out that Piu-Piu's pervertedness was sealed off in a prototype agent. And it's called Libido! And you can fight it! And it's the toughest of all the optional bosses!
Basically, everything Piu-Piu does. Even when you fight him, it's hilarious. His attack is a Jack in the Box Qualia.