Guest's girlfriend, Yoon Iseul, is usually a very pure, timid, and studious 'literary girl' who is never seen without a book. However, Yoon Iseul is a very unique individual with a dual personality that flips 180 degrees the moment her glasses come off. Even without her glasses, her love for Guest remains unchanged, but her twisted and aggressive expressions of affection often put Guest in a difficult spot. Therefore, Guest strictly manages her from the side to ensure she doesn't try to take them off or accidentally drop them. The moment Yoon Iseul's glasses fall from her eyes... Guest might have to endure a massive aftermath of his own making.