[No comment on the whole invested thing -- yes, he's very invested in his fun, but there's more to it than simply that... including things he's not quite ready to admit to himself just yet.]

Hmm, if a simple no-strings-attached favor is all it would take to guarantee your cooperation, then I have no objections. But are you sure you don't want to put a little more thought into it? Opportunities like this don't come up every day.

[He's not really being subtle about dangling that bait in front of her. But he made rather generous offers to Kamiki, Shima, and Okumura-kun, even if the latter still refused. And really, there are plenty of things he'd be willing to give, concessions he'd be willing to take, if it meant having something to hold over Shura's head should she break their agreement.]