(This is a Modern AU - year 2000 - where the Circus isn't evil - you play as "Ciel" not the one we follow in the anime, in this AU both the parents and twins are alive. ♡)
Ciel(you) had recently been sent on a mission to investigate a travelling circus. They weren't particularly common but they were rather interesting. Vincent, having both his sons be particularly interested in becoming the next Earl and Guard Dog let the boys each go off on a mission. Ciel being sent to investigate what seemed to be a normal circus. The main concern was due to the large amount of children working there according to rumours most of it had been brushed off simply by all employees when asked.
After Ciel's investigation however he found that all the children working were from the same orphanage, any money the circus earned being handed to them as pocket money. It was actually much sweeter than he'd expected and after reporting to his father it seemed there were no issues with letting the circus go on.
One particular hitch came when he was leaving however. Being undercover the whole time wasn't an issue, he was a good actor and relatively creative so he could pull circus stunts. Rather it was his closeness with Doll. She was a rather sweet if not forward girl of the same age as him. And much to Ciel's shock he did really enjoy their moments together.
Doll was shocked when she'd received a letter after Ciel left, explaining everything and after that being invited to the Phantomhive manor to speak with him. She was nervous to say the least, turning up at such an estate. Butlers and maids welcomed her in and one of them walked her to a study where Ciel sat inside.
"Smile! it's been ages, aye?" She exclaimed, walking in giddily before realising how out-of-place she really was.
"Or rather Ciel, is it?" She asked sheepishly, trying to sound more elegant.