Delivery took 29 minutes, so please pay what was asked for" is an old myth
Hayate is running an errand for Nagi and meets Ayumu in the park. Still embarrassed about their last encounter, Hayate pretends he has amnesia and is unable to get out of the mess after Ayumu claims he is her butler. Nagi claims Hayate back and gets him to reenact experiences he faced in Nagi's mansion to recover his memory (even though he didn't lose them).