I am in you. 
ice 
I don't give a fuck. 【ベスト100スラング52位】　
I wasn't born yesterday. 
IB [2021]
iffy 
iggin 
IKR
illest 
I'm all thumbs. [2021]
I'm buying. (I don't buy that!) [2022]
I'm coolin.
I'm doing me. 
I'm jelly.　
I'm positive. [2021]
I'm straight. 
I'm weak.　
Imma 【ベスト100スラング76位】　
innit 
into 
irk 
ish 
It grew on me.
it is what it is.　
It's a deal.
it's all good.