Hanyou no Yashahime: Sengoku Otogizoushi

The obvious recommendation: Watch Inuyasha before you start with Yashahime because the anime depends on the established lore from Inuyasha 

Strong Female Protag's Alternate World Switching Folklore Relationship Building 

Both involve 2 people separated by time travel then reuniting. Even more specifically, the time separation is supposed to be between the Sengoku era and the modern day in both. Both of these works were also created by Rumiko Takahashi. 

I think Hanyou no Yasahime is the "perfect" anime to recommend after someone watches Boruto, especially to those who watched the OG animes as a child that Boruto and Yashahime are sequels to. Both series have poor writing the same level as mediocre fanfiction and disrespect a majority of the characters from their respective original series, especially the female ones (though Naruto females were always poorly written). Watch Yashahime to further ruin your childhood if you had problems with Boruto.  

three girls on a magical journey sometimes simping on returning to the real world between episodes... really dense and pedantic. meeting foes and friends in side stories, but the goal is to reach an evil boss that... it's not that bad, yeah tweest. their weapons and powers unlock yada yada. but hey, someone must save the Tokio tower! 🤣