What is 「せえいの！」？

[Janet Merai]

This phrase is also heard on one of the songs for "Lucky Star" in one of their weird short songs.

It sounds like "saaaaaay nou!" but more like a sort of catch-phrase and it has a particular tune like a familiar tune recognized in a song.

To make it more obvious, it seems like a way to start something or a cute way of doing something.

After hearing it so many random times, I am curios as to what this means... any ideas?

 

[Glenn]

It's used as a sort of "1, 2, 3" to coordinate the start of some action between people. I had always thought it was せいの, but I've never actually seen it written. Does that sound about right?

 

[Glenn]

So I was thinking about this some more, and it seems to me like it has to be either せえの or せいの, because that gives you three morae, which is similar in rythm to the English "1, 2, 3" with the fourth beat being when you start doing whatever it is you're about to do. At least it seems that way to me. I'd never thought about it before. I had always thought it was two units, but this makes more sense.

 

[Janet Merai]

I used 「せえいの！」 because I tried to match it as one would express it more.

But in actual context, I believe it is either 「せいの！」 or 「せえの！」。

Any native Japanese speakers to confirm this or correct this please?

 

[Toritoribe]

「せえの」の検索結果 - Yahoo!辞書

As you can see, the entry word in the dictionary is せえの. But, as epigene-san wrote in the thread linked below, it would be the most common to be pronounced as a long vowel せー.

ｾｰﾛ？せいろ？ | Japan Forum

 

[Janet Merai]

ありがとうトリトリべーさん：３

今、分かりました。

そして、ありがとうで教えた。

せーの！ありがとう！：３

 

[WaterFox]

せいのー is oops-a-daisy, upsy-daisy, upsidaisy.
せえいのおー is ooops-a-daisy, I think.