The protagonist is a girl who can see ghosts. She pretends not to see them because they kill people who do. I think there might be eye drops/drugs that is being shared around in her school that allows people to see.

Could it be Mieruko-chan https://www.mangaupdates.com/series.html?id=151289 ?

Thanks but unfortunately no. This series had a more serious horror tone. No comedy as far as i can remember. I remember a scene where she was on the bus and she did her best to ignore this ghost, but the ghost was keen on killing her. She was able to escape in time when she meets her mom i think. Some girls in her high school got killed earlier in the series. The eyedrops they used to get high allows people who usually cant, to see ghosts temporarily. But she can see them all the time. She kinda “mentors” her classmate who used the drugs but for some reason the effect didnt wear off.