Sui Shijima (四十万 スイ, Shijima Sui) is Ohana's 68-year-old grandmother, mother of Satsuki and Enishi and the owner of Kissuisō. She has a fierce and strict composure towards her employees and holds no hesitations in physically disciplining them. She also doesn't wish for any radical changes to the inn, such as those suggested by Takako Kawajiri, the inn's business consultant advisor. Her abusiveness leads Ohana to believe she is going senile. As revealed in Episode 3, Sui actually had some confidence that Ohana would change the staff of Kissuisō while she is praying at her dead husband's shrine, mentioning with joy that she's just like "her". It is also shown that she does not want to put too much of a burden upon the staff members, showing that she is very responsible at heart.
- Sui is able to clean the inn's baths by herself from disorganized to almost purely clean within 15 seconds. This shows her capability of an exceptional inn waitress.