Kugenuma Hanazawacho 2-1 Casual food to nibble on and a remarkably large cocktail menu. Open 6pm-5am daily. Open every day.
Lunch is a much better deal than dinner.
Not actually on the beach, but a good place to fuel up on your way to or from Enoshima beach. Just because you're on the beach in Japan doesn't mean you can't have frozen seafood imported from America. Open 11am-11pm daily. The best Italian food on the entire coast, with great antipasti and seafood. No need to have a full-course meal.