I apologize for asking stupid questions: Are these three cuties Kana's little sisters? And, what are their names?

No, Somebody screwed up the tag.
Those are Hajime's little sisters. You see them in a few episodes.

Well... do they have names?

Ribonizer said:
No, Somebody screwed up the tag.
Those are Hajime's little sisters. You see them in a few episodes.

Are you sure? The only time I'd seen them was a brief cameo. And they were with Kana; not Hajime.

I hope they get named soon.

They're definitely Ikeda girls. Their names are Hina, Kina, and Nasa.