On the night the commander and Illustrious just got married, Unicorn stumbles upon them having fun in their bedroom. What she sees there spurs her to make a “night visit” of her own to her Onii-chan (the commander)’s bedroom the following night.
She may be inexperienced, but her thirst can not be quenched with going all the way!
...and somewhere along the way Illustrious joins in for a very passionate threesome.