Except for Nagato, they all existed prior to 3 years ago, just possibly not in the same form as now. For instance, Koizumi says he didn't notice his esper powers until just 3 years ago.
Nagato would have to eat 3 or 597, depending on your point of view.
I can't help but notice Koizumi is "staring at her like that"... with his eyes still closed.
It's an anime thing. Just ask Brock.
Why are the two of you staring at me like that?What!?
No-You know Mikuru-chan, on Setsubun, beans aren't just for throwing, you also eat one for each year in your age.Really?Let's see...One,
Two,Three...StaaaaareDon't mind us.
Please, continue counting.