Tomo can 'win' this easily. Carol already showed the way. Jun cannot ... let me repeat that for the people in the cheap seats ... CANNOT handle a sexually forward woman. Hell, the boy was traumatized when Carol put her boobs on him and tried to kiss him. If Tomo would just get over herself the fight would be over and Jun would be saying 'humanahumanahumana'.
Also, something tells me that 900 sounds like a good round number to end this manga on for some reason. If Jun faints during the date due to some Carol taught shenanigans from Tomo he could wake up to a calm Tomo lap pillow that develops into a real kiss. And they live HAPPILY EVER AFTER ... THE END. Until they have like 16 kids and break ALL the beds.