Please Help Me, SOS!

Synopsis

I have a childhood friend who's just missed his first lecture. Top Student Jang Sian. He's never missed a class, and he's never gotten anything lower than an A+. Although my grades are not comparable to his, we've been friends ever since we met in middle school. We've stuck together since then and now, even in college, we're inseparable. It's because of this that I thought that even if we showed a new side of ourselves to one another, we'd be able to move on from it without a hitch. However... Who knew that there would come a day when I would be fingering his asshole...?!