I'm still at work, in Japan where it is 8:25PM now. 

I am staying back at the office still since I was attending a meeting all day long, and didn't get any work done.
Japanese employers likes expect you to work overtime a work. There Here they think it is natural for employees to go about they are come back home late,  
but I don't want to be like that, I don't agree with this 'custom' so.
As can be seen from these sentences, I need to study more English...  (but we understand you perfectly)
I want time to study English more often.

I'm still at work.

In Japan, it is 8:25PM now.
I am still at the office, since I was attending a meeting all day long.
Japanese like to work.They think it is natural to come home late.
But I don't want to be like this.
As you can see from this sentence, I need to study more English...
I want time to study English more.

Great job with these sentences ! I know how you feel about people staying late at the office all the time and not wanting to be like them...