[Quarkboy]

More niconico douga words:

Nakamuraya! 中村屋 and it's more recent variation Shameimaru! ＼射命丸／

Originating from a flash animation, which was in turn created from a comedy track off a CD by the musical comedy group グループ魂 called GROOPER whose basic joke was:

A man tries to give a standard speech at a wedding party, but a couple guys in the audience act as if it's a kabuki performance and constantly do kakegoe (shouting the person's name, in this case "Nakamura" (with an extra kabuki style honorific -ya))... but kakegoe is a lot more complex than just the name and you can shout out things that sound similar to the name or, well in any case the original of the joke is in kabuki.

The flash video was somewhat popular on niconico, but a recent parody version with Aya Shameimaru from Touhou has eclipsed the original in popularity and any appearence of Aya in videos will often be met with the ＼射命丸／ comment, which, as you can see from this twisted history I uncovered, actually a traditional Kabuki kakegoe.