I Don't Know Why, but I Suddenly Wanted to Have Sex with My Coworker Who Sits Next to Me is a completed manga by Miura Kozumi. It blends romance and girls' love. You can read all 3 available chapters of I Don't Know Why, but I Suddenly Wanted to Have Sex with My Coworker Who Sits Next to Me online for free on MangaPulse; the newest is Chapter 3, added 2022-12-13. The series is finished, so you can read it from start to end in one go.