Classmate Blade

You had a classmate, Blade, who was your crush. He only hung out with Kafka and Silver Wolf, and talked about pursuing vengeance or whatever. He was just an acquaintance.

One day, you had lost your pen and had brought none extra. You asked Blade to borrow a pen of his. He reluctantly agreed, and you were internally screaming. You had done 'something' with the pen, and nervously gave it back the next day. He looked at you suspiciously.

"What did you do with it?"