You'd know when it's 'Hayaguchi kotoba' time when you've got the day's selection of guest singers lined up in the same manner as a school/church choir while donning a white gown plus hat thing that looked like a beret. Then we have leader of The Drifters, Chosuke Ikariya (いかりや長介), in his own black gown pretending to be those conductor or instructor or whatever you call it saying those faithful words to get the show on the road:
"Ladies and gentlemen, this is Hayaguchi kotoba!!"
The tongue twisters, which I think get tougher and tougher as they proceed, were drafted by Ikariya himself and the rhythmic music was composed by Akihiko Takashima (たかしまあきひこ).
In the video above, The Drifters had brought 'Hayaguchi kotoba' to the Kohaku stage during what seemed to be their only but deserving proper Kohaku appearance in the 52nd edition of the year-end show in 2001. Contenders include the apparently 8 year-old Akko-chan and 9 year-old Mae-Kiyo. (Unfortunately that video has disappeared but I found a replacement. -- J-Canuck)
I had remembered watching a clip of 'Hayaguchi kotoba' on '8 Toki dayo! Zenin jugo' where Shimura came on as the last contender and stripped down to his highly suggestive (to put it nicely) swan tutu. Unfortunately, I can't seem to find it now... sorry for those who want to see the raunchiest member of the group in the tutu while singing this song a squeaky voice. But here, have this instead...