[Buying dinner sounds like a perfectly fine prize to him, and with his confidence, he's certain that they'd win it- and subsequently probably ending up paying for the outing after their prize dinner date, so it would end up being even in the end anyhow. He's more in it for the fun and satisfaction of a healthy competition anyway, and testing himself in new ways, even if it's something as simple as a piggy back race around an apartment building.

And it would be nice to have an excuse to go out with the two of them again. Tartaglia definitely wouldn't mind at all spending more time with them.]

Then it's settled.

[He replies with a smirk, shifting Yoimiya on his back in a way that's most comfortable for him, getting himself psyched up for this race.]

Let's start here, [he says, conjuring up one of his own hydro blades that snaps into existence into his hand and sinking it into the grass.]

This will be our starting point and finish line. I don't think I need to explain the rules, just line up behind it and get ready. Perhaps the girls can yell when we can take off? No cheating now, you can't give a little squeeze to tip us off that you're about to start the race.