Chiaraijima Kanako wa Naze Marumaru Suru no ka?

Tsuchiya Narumi wants to stay in Japan for high school while his parents move overseas for a new job so he decides to move in with his distant relative Kanako. In public Kanako is a respectable, hard-working career-woman but when she's at home she acts in a very different way. Is Narumi the only one that knows what her true personality is like?

(Source: Ura Sunday, translated)