User blog comment:Hetare!Hetalia/The character songs.../@comment-3101158-20101104161233/@comment-3162677-20101104162649

I think he's talking about Feliciano (Italy) and Kiku (Japan), They were Ludwig's first friends after all.

"Though they say I eat only potatoes,

They're the same with soba and pasta"

^ Biggest hint that he's talking about Feliciano and Kiku.

Thank you Pary16 for the correction.