I mean it was kind of obvious she wasn't interested in Shogi... But I think she'll probably become a wingman, not a rival, after she realizes the real reason Ayumu joined.
Amano has such little progress I wouldn't even consider it a romance, just pure Ecchi with panty shots. The rival is an actual instance of a character being assertive, but we both know it won't go anywhere.
Amano Megumi is the quintessential Manga that will end almost immediately after the confess with a shitty time skip showing them married with kids before it ends abruptly. I'm calling it now Amano will move to another country for a Kendo Scholarship pre-time skip, just to have him forced to confess.