Adventures in the Bible: Main character Mei Ayazuki is sent back from present day to Meiji Era Tokyo, where she encounters many real-life historical figures in her month's stay.
Continuity Cameo: Koyo, Rentaro, and Taikan all appear in the 2019 anime for short amounts of time.
First Girl Wins: While Charlie is the first boy Mei meets, it is Ougai who picks her off the road and gives her a place to stay. The Visual Novel lets you pick which route to take, but the 2019 anime heavily favors Ougai.
Harem Genre: The reverse kind, with 7 boys in the original Visual Novel, 8 in the 2015 movie and 2019 anime, and 11 in mobile game Haitara Date.
I See Dead People: Mei has had the natural ability to see ghosts since she was a child, which is the reason why she does not have many friends in the current day. In the Meiji Period, she is known as a Tamayori, and is highly prized because of this.
Kyoka and Tosuke are also Tamayori.
Yakumo used to be a Tamayori before he injured his eye.
Goro is not a Tamayori, but can see the reflection of the spirits in his cursed sword.