Unable to answer "What are the opening hours here?" – Gastronoms (Convenience Store) – https://osm.org/node/2841576659 via StreetComplete 58.2:

Kawaii sushi restaurant, looks like takeaway only or courier pickup point only, Mon-Sat 11:00-23:00.

Attached photo(s):
https://westnordost.de/p/230792.jpg