Ah, hey! You've got a text!

Wakabayashi-kun: Thank you so much for the marshmallows. I'll pay you back threefold, that's a promise. - Hige Habahiro Full name woo! "Hige", as it turns out, is his actual surname, using different kanji from but homonymous with the Japanese word for "mustache" (in case you hadn't gotten that joke already). His given name, "Habahiro", literally just means "wide", and is unlikely to be given to children outside of gag manga like this.

Good thing I gave it to him, huh?

Say, since I know her home address now, too...

The next day:

Three boxes of chirimen jako were delivered to the Wakabayashi residence. Chirimen jako = young sardines. Remember Hige's misunderstanding?