I read page 1 and thought “man someone should write a yuri story where they’re anonymous pen pals and they exchange letters through some weird way like leaving them somewhere, like some message-in-a-bottle-type shit, but then surprise twist there’s time travel involved and they’re actually separated by 100 years! That would be cool, too bad this manga won’t be that.” Then I saw the letter fall out of the 100 year old book and I was like “wait” and then the author of the letter used some awkward wording to refer to the time period in which the book was written that seemed to be deliberately avoiding implying whether the writer considered it to be the past or the present and I was like “hm” and then there was the scene where the MC’s friend complains about “not knowing the future” while otherwise being irrelevant to the pen-pal plot and I was like “hm!” and then the author straight up made the message-in-a-bottle comparison directly, complete with illustration, and I was like “I see”
And then I finished chapter 2 and I was like “oh.”
…but what if?
This storyline has been used quite awhile now-- about how one accidentally became pen pal to another but they are unaware that they are from different times, mostly het love stories.
The one I remember the most is from "Tales from the Unusual" and starred by Morikita Maki san.
Oh but there's English version too.
The Lake House by Keanu Reeves.
I'm trying to think if such premise storyline has been used by yuri mangas.
The only ones that have exchange words are scribbles from the table and both of them are in the same timeline--
Furutsuji Kikka sensei's Graffiti.