Seiko waved at Tom with a wide grin, slightly perplexed by his reaction, then looked over at who she was standing near to. Kozue and Misaki were in bikinis so of course they'd get a reaction, she nodded to herself, mystery solved. Completely forgetting temporarily she too was in a revealing bikini and thus may be a contributing factor too.
With a sigh and a roll of her eyes she waved back to Kanaye, pretending not to have heard his comment, "Hey Kanaye-kun, I'll swim later..."