Izumo: Takeki Tsurugi no Senki

Since his parents passed away, Yagi Takeru has been residing in the Tma family's residence. Tma Rokunosuke, the household's leader, raised him. He is surrounded by a large group of individuals, including Osu Seri, his childhood friend, Yamato Takeshi, his best friend and rival from the kendo club, the Shiratori sisters, Kotono and Asuka, and many others. Up until one day when an earthquake hits the school, everything was perfect. Takeru awakens to discover the school in ruins, as if it had been abandoned for generations. He also notices that all of the instructors and pupils have vanished. When he reunites with Seri and Asuka, they have already evacuated the wreckage and discover that the town they once called home is entirely deserted. People wearing cloaks then emerge in front of him. They were informed that they had been transported to an other universe. Takeru was tasked with having a relationship with a princess of this realm and giving birth to a warrior who will one day alter the course of history.