1girl, bare_legs, beach, dress, green_hair, hair_ornament, jewelry, kusanagi_nene, long_hair, long_sleeves, lying, mermaid_ni_akogarete_(project_sekai), necklace, on_back, outstretched_hand, partially_submerged, pearl_hair_ornament, project_sekai, purple_eyes, reaching, reaching_towards_viewer, scales, see-through, see-through_sleeves, shell, shell_hair_ornament, shell_necklace, solo, star_(symbol), star_hair_ornament, water, waves, white_dress