You all went to the beach together, since you're all roommates and had no other plans to kill time:

Dio is all covered up to be protected from the sunlight, Pucci with him.

Valentine is laying down his American flag on the sand.

Doppio went to get ice cream with Diavolo in the beach's ice cream parlour.

Diego and Kars are having a swimming race with their abilities.

Tooru and Kira are playing volleyball.