Ambush them in the locker room

After an additional 10 minutes of swimming, Chihiro and Aoi finished swimming and went to the locker room.

As they walked into the locker room, they noticed that the lights were off.

Aoi fumbled around in the dark, trying to find the light switch. Chihiro held the door to the pool open so there was some light.

"H-Hey!" Aoi yelled out in the darkness, Chihiro was unable to see her.

Chihiro went into the darkened room to see if he can find Aoi. "Are you alright?" Chihiro called out but got no response.

Suddenly, Chihiro felt someone grab him from behind, his mouth being covered by someone's hand, muffling any sound Chihiro made.

Both he and Aoi were at the mercy of their ambushers.