Mr. Tines: cf. Jun's school shoes in Rozen Maiden (being the only other instance that comes immediately to mind)
Pluto: Since all students have the same uniforms and shoes it's common to see students write their names and class numbers on them in case they get lost for some reason. Not everyone does this but it's pretty common.
UrsusArctos: I was wondering why Asuka wrote her name on her shoes! If everyone is changing nearly-identical shoes upon entry and risks mixing them up, it makes absolute sense.
thewayneiac: Maybe I shouldn't mention this, but I recall that this scene really confused our old friend Reichu, who obviously hadn't seen enough anime. She thought these were letters from an ex-boyfriend in Germany.
