What does the Japanese in 'Polyphia's "ABC" feat. Sophia Black' mean?

The Japanese lyrics in Polyphia's amazing song "ABC" go as follows:

[The phonetic bit]

あいうえお 
かきくけこ 
さしすせそ 
たちつてと 
なにぬねの 
はひふへほ 
まみむめも 
やゆよ 
らりるれろ 
ぱぴぷぺぽ

This translates to:

Aa ii uu e o 
Ka ki ku ke ko
Sa shi su se so 
Ta chi tsu se to 
Na ni nu ne no
Ha hi fu he ho
Ma mi mu me mo
ya yi yu ye yo 
Ra ri ru re ro
pa pi pu pe po

This is basically something along the lines of an alphabet song for Japanese. This is not the complete song either and some license has been taken with a couple of lines here :)

"Na ni nu ne no" could also mean something like "what's wrong?" when put together.

This use of Japanese phonetics ties in with the lyrics in the chorus:

Someone call a paramedic  
I can’t speak it’s all phonetic  
Made me forget every word cause like that’s a lot of letters 
Abcdefghijklmnopqrstuvwxyz 

[Spoken bit]

えちょっと待って 
ちょっと待って 
イケメンじゃない？ 
イケメンだよね？ 
むり、むり、むり、むり 
ヤバイ、超かっこいいんだけど。 
むり、むり、絶対むり 
ヤバイんだけど。 

This translates to:

Wait a minute
Wait a second 
Aren't you handsome?
You're handsome, right?
Impossible, impossible, impossible, impossible
That's crazy, but it's super cool.
Impossible, impossible, absolutely impossible
That's crazy!

FWIW, I'm not a Japanese native speaker or expert for that matter.

Hope this helps someone out there :)