Sone sort of word pun, Mogami (最上) lit. at the top.
The one written: at the middle.

Also monaka (最中) is a kind of wafer cake filled with bean jam or ice cream.

pellaeon said:

Also monaka (最中) is a kind of wafer cake filled with bean jam or ice cream.

Hey! That is the monaka in this pic (just different shape.)

Translation updated!