Netorare no Kyoudan ~Oshiego ni Ubawareta Ai Suru Koibito

Two years ago, teacher Hayasaka Jo decided to date student teacher Minase Saki after she confessed her feelings to him.
The two slowly grew to love each other.

Time passed, and Saki, now a teacher, was hired at the boys' school where Hayasaka teaches, but
they kept their relationship a secret from those around them, intending to maintain a relationship as superior and subordinate until they got married.

One day, Hayasaka witnesses a student named Hotta Takaaki, who is good friends with Hayasaka, forcibly taking her to a love hotel.
Hotta is a student in Saki's class.

Could it all be because they kept their relationship a secret?
A student alone with a beautiful teacher after school.
A sexually charged adolescent.
And Hotta's lust-filled gaze directed at Saki.
All the conditions were right for "something" to happen...

[Translated from Getchu]