Fighter seen in Japanese clothes (5)
I believe the answer is:
ninja
'fighter' is the definition.
(I have seen 'Japanese fighter ' mean 'ninja' so perhaps 'fighter' could also mean 'ninja')
'seen in japanese clothes' is the wordplay.
'clothes' indicates a hidden word (the letters clothe the hidden word).
'NINJA' is hidden within 'seen in japanese'.
(Other definitions for ninja that I've seen before include "Animated turtle" , "Stealthy warrior" , "Practioner of ninjitsu" , "Japanese spy or assassin" , "Teenage Mutant ... Turtle (toy)" .)