In Sapphire's introduction scene, she's blasting monsters...and lamenting that she's sending fellow students to the darkness. Then Almaz, in Save the Princess mode, rushes up to her...and gets blasted too. Sapphire and Mao then hit it off when the princess admits to being a 'killing machine', much to Almaz's horror.
Raspberyl and Co.'s Big Damn Heroes moment is sidetracked by a stunning revelation from Mr. Champloo- they're graduating! What follows is an utterly hilarious and played-completely-serious graduation ceremony, while the final boss of the level sits on the sidelines and waits.
Nearly any scene with Champloo. While we see there's some Hidden Depths to him, his dialogue, especially the early stuff, is still hilariously insane, especially since Mao and Almaz actually agree that they can't make any sense out of it.
Sapphire, at one point, decides to take action to open Mao's heart. With a chainsaw. Mao and Almaz have the predictable reaction, and Sapphire says that she heard demons can't die from things like this, to which Mao says is a lie and runs away. Sapphire chases after him and says that maybe a chainsaw was too painful she'll use a surgeon's scaple instead.
Almaz finding out Mao's father in the second encounter has a plug and being plugged into a wall socket.
Upon achieving "Mao's ambition" ending, you get this at the end:
Mao: Now that's come to this... The only option left is, to reset.
Mao's reaction towards learning Baal was the thief:
Mao: Tyrant Overlord Baal!? Wasn't he just a ploy to force players into playing their games for 1000 hours longer!?
One of the things you can steal while having a thief's evilty is "Balls".
Black Eyes Blue Prinny's description: Sacrifice 3 gods to summon a normal Prinny. Can't attack with White Lightning.
Likewise, everything involving with Se-to-oh.
In The Vita Updated Release, in final map of Master Big Star and Salvotore's scenario, We get this dialogue during the cutscene:
Prinny Clicks the "bomb remote".
Prinny: Oh, crap! I accidentally brought my TV remote! Dooooood!!!
Master Big Star admitting he done the same mistake also, and Mao lampshading on fail attempt.