你知道这句话是什么意思吗？

一、你知道这句话是什么意思吗？

Hey everything okay?

You seem a bit down today.

Yeah,I'm alright.

I just uh...woke up on the Japanese flg...

Huh?

Think about it.

I went to sleep on a white bedsheet.

but I woke up on the Japanese flg.