Otoko ni mo Onna ni mo Naru Couple ga Onsen Ryokou no Tsumori de Rabuho ni Iku Hanashi

The original author of Zenbu Kimi no Sei creates a completely original after story. You can read it without any worries even if you don't know the original work. It is a loving romantic comedy between two university students.
(Source: Toranoana, Translated)