Nothing at first

After all the contests in the locker room, the girls and Chihiro finally managed to get changed into their swimsuits and go into the pool.

Chihiro's swimsuit was made for his size so it fit well and as much as he never wanted to admit it, his dick was small enough that it wouldn't be noticed unless you looked directly at his crotch.

Chihiro was naturally having fun with Aoi, he was a bad swimmer so being taught by someone who knew what they were doing.

While they were playing, Junko and Sayaka were sitting on the edge of the pool talking to each other.

"Are you sure we can't do anything yet?" Sayaka asked.

"Not unless you want to piss her off." Junko responded as she pointed at Sakura, who was a literal mass of walking muscle and who was very protective over her friend Aoi and the weaker boy Chihiro.

They had to wait for the right moment to do their plan.