Herami Shimai wa Docchi mo Yanderu

Sera, (Real Name: Herami Fukasera) is an approval-seeking girl (26 years old) who works at a maid café. Her younger sister, Kira, is an idol (19 years old) who is rapidly gaining popularity with her cool, and mature character. However, the real Kira only ever thinks of her sister and tries to cheer her up in every possible way to help her sister with her mental health and anxiety.

(Source: Ichijinsha, translated)