班主任是容嬷嬷失散的女儿
[bān zhŭ rèn shì róng mā mā shī sàn de nǚ ér]
'The homeroom teacher is Lady Rong's lost daughter,' combining modern school life (homeroom teacher) with a character from a historical Chinese TV drama (Lady Rong), humorously imagining the homeroom teacher as part of a fictional past narrative.