Futanari Shoujo Kinryouku ~Ijou Seiyoku Kankin Gakuen~

The main character, Naomi, made her dream comes true and started working as a teacher in an isolated school in the mountains.

However, she noticed an abnormality in the school.
She found two girls petting together in the classroom, and they had something between their legs which they were not supposed to have.
They panted and ejaculated the white liquid.

Naomi was confused with what she saw.
And the encounter with a girl lead her to further abnormality...

In the crazy world, Naomi finds out the secret of the school.

[From DLSite English]