usui ve hosoi arasındaki fark nedir?Sadece örnek cümleler vermekten çekinmeyin.

usui: like thin, flimsy
hosoi: like thin, slim, narrow

they have more other meanings, but now putting that aside...

usui gives us a impression like a thin paper.
hosoi is like cylinder shaped things which have thin diameter.

For example,
When you use these to explain someone's figure,
usui makes us imagine a body like flat as a whole like a paper.
In some cases, it'd make us imagine that he/she is perhaps skinny or bony.
hosoi makes us imagine a slim/lean body.
We rarely use usui to explain about bodies, though.

I hope this will be of some help.

I came to know that both usui and hosoi are "thin" in English.
It was interesting :)