I feel like there's a joke I'm missing with the 25252 combo, that everyone's laughing at.
I mean, I understand it's from a rhythm game (I guess?) but I don't get what it has to do with...the bathroom.
252 reads individually as "ni go ni" in Japanese, which sounds similar to "nico nii".
25252 is the same but extended, so it's "nico nico nii".
Nico also has 25 on her underwear, which reads as "Nico".
Damn it, Japanese and their number puns.
Having picked up a vocaloid game recently, it took me an embarrassing while to realize why "39" was associated with Miku everywhere. This is pretty good, though...except that Maki thinks about Niko whenever she...
hm... = \