Ok so the likely implication is that shinope is the girl that sakine was in love with.
Only question is what she had to do with the bullying.
I feel like the manga wants us to think that she was on board woth the harassment, but its entirely possible from what we know of her character that sakine got shinope bullied (the fact that she had a whole name change and seems to have it out for sakine makes me think it might be this). Excited to see more, thanks for the chapter!