Apparently Oshikiri Rensuke is working on another work in the series for this. Perhaps a sequel?
https://www.animenewsnetwork.com/interest/2019-10-04/creator-rensuke-oshikiri-says-he-working-on-a-new-hi-score-girl-project/.151839
The second season of High Score Girl will air on the 26th Oct 19 with 9 episodes.
As for the manga, there are only 4 more chapters left with the final chapter being c63.
Hopefully it gets completely translated soon.
I read the raws and the ending was
quite clichéd. Akira wins against Haruo, accepts reality and decides to cut ties with Haruo by returning ring(first gift from the gacha).
On the day of Akira's departure Haruo sulks, lingers in the streets, meets Koharu and gets scolded, who tells him to say his farwell to Akira at the airport.
Then the usual dramatic race against the time to see each other before the airplane departs.
We get some ambiguous drama with the airplane flying away after Haruo arrives.
But after all he could still meet Akira, give the ring back, they cry and make some promise. In the whole manga Akira never ever spoke a word.
Don't have the skills to scanlate the last few chapters, but I read ahead to the end.
The "some promise" mentioned by @Eviltwin is actually
Major ending spoiler; consider yourself warned.
Haruo proposed - "With this ring, will you become my bride?" After this is a bit ambiguous, but it's heavily implied that she accepted. She keeps the ring.
Please please translate the next 3 chapters. Do you have a patreon or venmo, I'll give you 20 buck. I know it ain't much but I'm kinda broke. I really really wanna read the next few chapters, so please translate them