Their first baseball game is coming up, but the Little Busters are still one member short of a full team. And no, I don't mean that as a euphemism for them being dumb, although now you mention it...
Of course, there are no prizes for guessing whose job it is to find this final member, but surely it can be no coincidence that the very next practice session for the team as it stands ends with the ball hitting an innocent classmate and proffering an opportunity for Naoe to talk to her. The classmate in question is bookworm with a parasol Mio Nizhizono, who unsurprisingly doesn't enjoy being hit by a baseball too much, and isn't exactly the warmest or most talkative of conversationalists at the best of times.
This isn't the kind of thing to put Naoe off however - indeed, he seems rather drawn to Nishizono given how her behaviour as a loner who nobody else even seems to notice reminds him of his own past, and thus he finds himself spending more time with her, with an eye towards possibly inviting her to join the baseball team even though she's as far from the sporting type as you could possibly get. Ultimately, Naoe is co-opted into the search for a book that's precious to Nishizono, and in spite of Mio and Naoe's assumption that it's probably been stolen or otherwise hidden for nefarious reasons it turns out that there's actually a completely innocent reason behind the whole thing. With the gap between the two of them at least somewhat closed, it seems that Nishizono is willing to watch the others play baseball as a result, if nothing else.
So goes another passable yet unspectacular episode of Little Busters - Nishizono isn't really the most exciting of characters, and the potentially interesting parts of her story are as-yet not revealed, so what we're left with this week is a pretty run of the mill introduction to her while moving another step closer to a full baseball team. If nothing else, this could signify the fact that we're getting closer to the interesting part of the series - at least, I hope that's the case.