Ci, it sounds like an elder calling a younger one, or a sister calling a brother.
Yu Xia really likes being a sister, just like how she gets excited when she hears the word 'brother.' But to seriously call him Ci, it still feels a bit odd.
Calling it a few more times just makes it even stranger.
The mix of awkwardness and embarrassment made her uncomfortable all over, so she put down her cup and dragged him to see the "temporary room" next door.
The room next door isn't as big as the main or side bedroom because he piled up many books there, further reducing space. His parents hadn't tidied up the books, so with a bed put in there, it really does look crowded.
Xie Qingci threw himself onto the bed to test it out, then sat up curled around a pillow.
"It's still not longer than me. Sister, take me in, I come with a pillow."
Yu Xia imagined the scene and said, "If you come knocking with your pillow in the middle of the night, acting a bit pitiful, I might take you in."
