Hi so apparently u aren’t the only one looking for the story. I found an old mangago thread that was way back in 2020. This story plot is a freaking mystery. Some say its “Anata wa mada watashi ga sukidesu” but there’s no websites about this manga at all.
Here’s the mangago thread
https://www.mangago.me/home/mangatopic/8560471/?page=1 2 reply
Hiii. What ur sister is doing sucks. She shouldn’t be mean to you for no reason. Maybe she’s going through something. U should try to talk to her. I’m sorry about ur mom being sick. I hope she’s fine now. Stay strong for her . And I’ll be ur frienddd! U can message me here on mangago! I know what it feels like not having anyone to talk to...... reply