"Also, one of them is your girlfriend, right!? Tell me who it is so I can make a good impression!"
There we go, that's more like it. I don't even care that it was predictable, I love curious developments like this when it comes to family members in manga and anime. It just makes every teenage romcom story feel more natural.
Why, Mio is just concerned about her unsociable brother. Maybe a little too concerned, but better than than cold indifference or hot hostility. Given that she wanted to make a good impression with the girl who's potentially her brother's girlfriend, I can probably rest easy that her love for her onii-chan is wholesome and not the typical degeneracy more often found in some otaku-pandering series.
"The day you get a girlfriend will be the day hell freezes over.♡"
Concerned, but with a dash of perfectly normal sibling ribbing thrown in.Maybe hell should prepare for the coming winter soon...
This was so danged wholesome I teared up a little. And this is supposed to be just a birthday party for a supporting character! Why is this so beautiful, and emotionally fulfilling?
I see the side ship construction is well underway and perhaps nearing completion. Keep it up.