Yoshitaka-san is a plain, glasses-wearing, quiet accounting girl. I thought she was a hard worker who always worked overtime until late... But one night, I was working overtime with her and tried to talk to her as she dozed off, and on her PC, I saw a cosplay picture of her plump butt! Is this a secret account? The erotic images uploaded every day were of the plain accounting department's Yoshitaka-san! "Hey, isn't this Yoshitaka-san? This is," she said, and in exchange for hush money, she showed me her butt, and then... I made a big turnaround and she became my convenient sex friend! What a nice butt!