Wareta Cup wo Modosu ni wa

It’s been ten and a half years since Keita and Kippei started dating. But even after all that time, they realize they still have difficulties communicating after Kippei accidentally breaks a sentimental mug. Suddenly, Kippei is struck by a time-twisting phenomenon that gives the couple the chance to reflect on their time together. The eighteen-year-old Kippei wakes up in 2020, and the twenty-eight-year-old Kippei wakes up in 2010! Can the two reignite their relationship and sex lives with their partners from the past?
(Source: Seven Seas)