wawamachi, specter (arknights), arknights, absurdres, commentary, highres, 1girl, alternate costume, armband, bare shoulders, blush, breasts, covered navel, cropped arms, cropped torso, cross, cross print, english text, feet out of frame, greyscale, hair between eyes, hair ornament, hair ribbon, hat, holding, holding surfboard, large breasts, long hair, looking at viewer, looking to the side, monochrome, multiple views, one-piece swimsuit, red cross armband, ribbon, simple background, standing, surfboard, swimsuit, whistle, whistle around neck, white background