Ageha-pyon
I would like to plot out the character. I feel like it'd be easier if she's a first year or the same year as him and already has interest in talking to him. I think it'd be nice if this character is more responsible to contrast his slacker attitude.
Well, Isshin does need/want a secretary! So I think it'd would be a good choice! just so we can have the best of both worlds. Hell, we could even make a short history between the two.
PrincessKitteh
Well, he'll have some time for them to run into each other and become at least acquainted. She doesn't make fast friends(friends in general aren't her forte aside from Sachi, so he probably won't get better than acquaintanceship until she's spent time in his club), but he probably won't overwhelm her and scare her off, so he has that on her side.
I mean, even if he circulates it somehow that he's starting a soccer club, she could hear about it and find him to inquire about it. Oh, if it's about the umm.. 'advertisement' of the club, I could very well have that arranged to happen in my next post. you can't go wrong with a couple of punches and a very enthusiastic scream in the name of the soccer club!