Five-day Tsundere Live-in With A Sassy Junior Childhood Friend Reina Miyashita

I have a younger childhood friend. Our parents get along well, and when both families went on a five-day trip, I ended up looking after my childhood friend, Reina. Even though she acts cold, she's scared to sleep alone and crawls into my bed, and she's too scared and embarrassed to bathe alone, so she joins me in the bath wearing a school swimsuit. Fiery and cheeky but impossible to hate, Reina keeps me completely off balance! Could her tsundere, teasing behavior actually be a sign of affection!? A tsundere cohabitation life told from a subjective perspective!