Ba-ka Ba-ka

Original at IOSYS

There's a LOT in this flash, so some things you should know.
Playing Scarlet Weather Rhapsody should also help a lot, a lot of SWR-related things show up.

The "top" here is literal, as Tenshi is a celestial and basically lives up in heaven.
She's not that smart though =D.

Cirno is actually doing her easy mode spell card during the chorus of bakas.
You know, the one where you can sit right in front of her and never get hit.

Iku's Saturday Night Fever moves are pretty known by now, but yes she makes that pose to call down lightning.

Cirno's math problem goes something like this:
3 people get on the Touhou bus at Scarlet Devil Mansion, one gets off at Hakugyokurou, half a person gets on (Yuyuko is gnawing on the other half), 2 people get off at the Yakumo's house, how many are left?
The answer is zero, because there are no buses in Gensokyo.
Cirno does the Ranka Lee (from Macross Frontier) kira kira pose here before being run over by Yukari's train super from Scarlet Weather Rhapsody.

Patchouli's initial book reads "dameido", a pun on dame, and also a VIP copy pasta thread.
Basically a very bad maid.
Patchouli's book when she gets off reads "hetare shu", or useless master.

The drinks Reisen gives Cirno are from her power-up super in Scarlet Weather Rhapsody, they're made by Eirin.

This part I'm unsure of, but Cirno says she can't understand time but doesn't care because the round-eyed god (but nothing round here) says the three hands mean nothing.
Sakuya does her counter move from SWR, which of course is parodying Dio from Jojo.

I don't know what Cirno's paper says yet.
Keine's blackboard seems to be...a list of missions from Earth Defense Force 2017 (Notice the giant bug), a rather popular game on nicovideo.

Of course, Yukkuri siteitte ne is what is said during Keine's headbutt.
The Knockout graphic is from Scarlet Weather Rhapsody again.

Ends with another Saturday Night Fever Iku, cept the lightning comes down this time.