Kanade Otonokoji was out at the pool because Setsuka Chiebukuro wanted to meet up with her and Kanade entered the pool.

“There you are Kana..”

Setsuka says as she rushes towards Kanade with a knife and Kanade tries to open the doors but they were shut.

“You’re not escaping..”

Kanade was in a killing game and she need to fight back and Kanade found a taser and put it in her pocket before Setsuka could notice.