Chapter 7:

Fuutaro and Sakura were racing up the tower to get to the siren. There were many monsters in the way and Fuutaro and Sakura had to fight through them.

...

Ichika was worried about everyone. So, she sets out to find them. "Where are you going," asks Taro, "they're all probably dead by now!"

...

The rest of the sisters were watching as more monsters were coming near their hiding place.

...

Fuutaro and Sakura were still on their way to the top. Then they finally made it.

"We're here," says Sakura.

"But where's the siren," asks Fuutaro.

They then heard the sound and looked around. "There it is," says Sakura.

They all saw her, Umi-no-Kami.