Everyone from my part-time job decided to have a drink at my house. Although it's called a drinking party, we're cultured people who work at a bookstore, so we just have a few drinks and head home before the last train. That's how it used to be... This time, Umino, a new part-timer, joined the party for the first time. A quiet, earnest, and bespectacled girl who's well-liked by her coworkers, she drank heavily, perhaps due to nervousness, and before she knew it, she was completely drunk. After everyone from work had left, I went to help a drunk junior colleague, but I couldn't help but notice her big ass, and as I stared at her, she asked for anal sex! I was surprised by her sudden transformation, but out of a sense of responsibility, I helped her lose her anal virginity. I'd only fantasized about this girl, but she finally achieved her long-awaited anal orgasm with anal penetration! I ignited her pent-up sexual desire and creampied her asshole all night long!