So that's why Maruzen, Ramonu, Rudolf et al refuse to graduate.

NNescio said in comment #2611160:

So that's why Maruzen, Ramonu, Rudolf et al refuse to graduate.

But then how do you explain Light Hello and Sonon Elfie and Yunohana Bloom and Tokino Minoru /s being an adult OG of Tracen Academy?

Jnglmpera said in comment #2611166:

But then how do you explain Light Hello and Sonon Elfie and Yunohana Bloom and Tokino Minoru /s being an adult OG of Tracen Academy?

Well, the curse supposedly doesn't work if you forget about it when turning 20, or if you never heard about it in the first place. Could be either of these for them?