Let's not forget that Ichigo was expecting to do lewd things with him at one point at just seeing that aphrodisiac bottle.
Good-looking and good at video games? I feel like that's the most positive thing she's ever said about him this entire series. The sore loser Ichigo is saying that? I guess it might be partially motivated by survival instinct, because she (and we) don't know if imouto-chan is the type to fly off the handle if she insults him too much. I mean, she already threw a sharp knife at her brother... I'm sure Ichigo does not want to find out if she's carrying another knife with her.
I can almost hear imouto-chan's loud gasp on page 4... I don't think she's going away any time soon after hearing that.
A gentle reminder that a "family" restaurant is not a place to start a family or grow your family.