opening day flower gift; bouquet for a new store
Refers to flowers sent to celebrate the opening of a new business, such as a restaurant or shop.
I ordered an opening day flower gift for my friend's café.
Opening day flower bouquets were lined up in front of the store.
Compound of 開店 (かいてん, 'store opening') and 花 (はな, 'flower'), with rendaku voicing of はな to ばな.