Just realized something...
What Ranka knows (before she left for the Vajra homeworld):
- Sheryl and Alto went out on a date in Folmo mall; and Sheryl kissed him on the cheek
- Sheryl and Alto hang out together a lot (gossip from Nanase)
- Sheryl kissed Alto during the filming of Birdman
- Alto and Sheryl were hugging on the flight deck of Mihoshi
bad enough, right? BUT...
What Ranka doesn't know:
- alto broke his own vow not to go back to Saotome mansion just to see Sheryl
- Alto comforted sheryl (ep22) and more or less promised that he will stay by her side forever
- Alto (may have) decided not to pursue Ranka and join the SMS mutiny because of Sheryl
- Alto (may have) this time initiated kissing Sheryl in her darkes hour
- Alto and Sheryl sort of moved in together
- Most, if not all, of NUNS knows that alto and sheryl were going out
- Alto and sheryl shared another passionate kiss (ok, all the passion may have come from sheryl. but still...) before the final battle
- Alto decided that if he had to, he would kill Ranka
AND all this after Ranka had already told him, in no uncertain terms, that she loved him.
if she found all this out, I wonder if she would have been as optimistic in throwing that challenge to Sheryl at the end.