That is wrong about Japanese immigrants' child (5)
I believe the answer is:
nisei
'japanese immigrants' child' is the definition.
'that is wrong about' is the wordplay.
'that is' becomes 'i.e.' (short for Latin 'id est', 'that is').
'wrong' becomes 'sin' (I've seen this before).
'about' shows that the letters should be reversed in order.
'ie'+'sin'='iesin'
'iesin' in reverse letter order is 'NISEI'.
(Other definitions for nisei that I've seen before include "Second-generation American" , "Japanese Canadian/American" , "One born in the USA of parents who emigrated from Japan" , "Child of immigrants" , "American born of Japanese immigrant parents" .)