So Rion's plan is basically an NTR setup involving a long-distance couple. She’s taking advantage of the boyfriend’s loneliness and the girlfriend’s absence to try and seduce him. It’d be perfect if, when Himari comes back from Tokyo, it turns out Yuu’s no longer a virgin and the two of them had a brief but passionate affair. As far as Losing Heroines go, this isn’t all that bad. Rion at least got to take her rightful bite.