>>56355722IIRC, it's implied that every interaction with the Kimono Girls is a secret test of character. Presumably, you taking care of that egg proves something that makes you worthy of meeting Ho-Oh/Lugia. For all we know, it didn't even need to be a Togepi egg-- just one that was entrusted to you by a Kimono Girl (even though you didn't get it directly from her).
>Verification not required.