Man I'd be so pissedhaha. At this point, the author have a blast being a troll to everyone with this manga.
Imagine, making Yame just a background character who show up sometime to make Junichi (and us) remember she's the main love interest, before she is ghosted for another ten chapters.
I'll not even be surprised if he made them break up by the end of this manga along with an end phrase like "she was my first and I'll never forget her...maybe"