Xiao Denzi and Xiao Zhouzi are the faithful servants of Swallow. They were "given" to Swallow when she moved in to her own place (shou fang zi). Along with Xiao Denzi and Xiao Zhouzi, two other female maids Ming Yue and Cia Xia were also "given" to Swallow. All four of them are very loyal to Swallow because she treats them like family and not like a princess to a servant. Swallow hates it when servants calling themselves (nuo chai or slave). Since Swallow was not born in the palace she is not used to people calling themselves nuo chai. She ordered the four not to say nuo chai but to say "we". The four were very frightened because by saying "we", it meant that Swallow and them are the same class of people which is not true 'cause Swallow is a princess. After millions of reminders and the threat to take away their pay if they say nuo chai the four finally got used to saying "we". Swallow and the four became great friends. They also shared a lot of laughs and cries together.

*Note* The two maids that served Swallow is Ming Yue and Cia Xia. I could not find any pic of the two female maids so I'm going to include them in here instead of writing another character info. The two pics above are Xiao Denzi and Xiao Zhouzi.