Reminder of what Japanese restaurants do? (8)
I believe the answer is:
keepsake
'reminder' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for keepsake that I've seen before include "to remember one by" , "It serves to keep a person in mind" , "Remembrance" , "Something of sentimental value" , "Thing retained in memory of giver" .)