To get the obvious out of the way: this book more than deserves its 18+ rating. As the title implies, this is about sex and therefor has a lot of nudity and sex in it. It's explicite and uncensored, so be aware.
With that out of the way, if you're interested in a good story about being an adult and what casual sexual relations are like told in a briliantly funny way then this is for you. The protagonist, Miss T, is frustrated with her sex life in Taiwan and desides to travel to Japan for two weeks to have some good one night stands. With every encounter she has with men we get to see a new fun character while also learning a bit more about Miss T. There's the overly dominant guy, the guy obsessed with his cat, th guy who is overly anxious, and many others. Each makes for a fun story and it's fun to see all those situations play out.
The main reason why this book sticks aout to me and why I like it so much is because it's not as fetishistic as most other erotic fiction I've read. Part of that is that it's just more focused on being funny rather than sexy, but also because of how it is written and portraied. The art can be decently detailed but not as much as other works in this genre. I'd say about half of the book has more of a chibi art style which is how most of the comedic scenes are drawn. That being said, it is still explicite with nudity.
All in all, if you're on the market for a book like this then I would highly recommend it, more than any other similar work to this I've seen. I can't wait to get my hands on volume 2.