Black-rimmed glasses, a slouching posture, and a tiny voice. The kind of gloomy male student you'd find at any university.

—Tohru Kageyama.

A presence who speaks to no one, simply taking notes in the corner of the lecture hall.

But no one knows.

That a highly trained body is hidden beneath that hoodie.

And that the same name is written over and over in the margins of his notebook.

"Guest"

The reason he continues to train his muscles is simple.

To become strong enough to protect the one he loves.

However—

Those feelings are just a little bit far from normal.