A Forced Engagement

Arawi Kenji, a very normal high school student, just wanted a girlfriend. The problem is that he is neither handsome nor athletic to attract anyone. In fact, he is simply ignored by any girl who he even tries to speak.

His beloved grandfather knew his sadness. So he arranged something... AN ENGAGEMENT! Undoubtedly Kenji was against it when he heard that. However the engagement was already decided between Kenji's parents and that unknown girl's parents.

The good thing: the girl, Amano Suiren was Kenji's classmate and Kenji liked her.
The bad thing: Suiren obviously didn't like Kenji and didn't want this engagement to happen.
Worse: Surien's parents just wanted to get rid of her so they have forcefully decided this engagement.
Worst of all: If Kenji says "no" to the engagement, her parents would torture her in anger later like they usually do.

What would Kenji do? How can he respond to this situation?