My first thought when I read the last page was Don't tell me she's about to pull a your lie in April on me
Explination: (and Your Lie in April spoiler)
No like actually if you haven't seen it yet watch it before you read this or it will be ruined for you;The GMC of Your Lie in April has cancer and doesn't tell the MC or her friends about it until it's too late.
Side note: Watch/Read YLIA after this, I was sitting on my bed in shock at the end crying.