[throw101010]

Small clue here too, maybe more subtle:

> explained school director, Rosalina Pfirsich, looking up from her storybook

Pfirsich in German means Peach, as in Princess Peach :D

[adrian_b]

Also "project leader Mario Idraulico" (i.e. "hydraulic" in Italian) or "Safety coordinator Luigi Fratello" ("Brother Luigi").

[dasyatidprime]

The noun “idraulico” also means “plumber”.

[TeMPOraL]

Also the schoolteacher Yoshi Kyouryuu which apparently is the dinosaur.

[rmast]

They’ve also got:

> schoolteacher Yoshi Kyouryuu, mid-way through painting spots on eggs

[hapidjus]

There is also ”project leader Mario Idraulico”

[darth_aardvark]

You somehow identified the last possible, most obscure clue. Mario, Luigi, Rosalina, and Yoshi show up before that.