Sally and Susie are a set of identical blonde-haired eleven-year-old twin sisters who love swimming. Both of their swimming gear consists of the same items: a pink long-sleeved full-body rubber wetsuit, a pair of pink swimming goggles, a pair of pink rubber gloves, a pink swimming cap and a pair of pink flippers. Susie also wears a pair of pink, glittery fairy wings. The twins have different personalities: while Sally is much more excitable and goes to swimming training often, Susie is very sweet, tenderhearted and kind, and is often found holding her breath underwater.