Yusuke Tashiro, who longed for city life, managed to get into a prestigious school in Tokyo. He was disappointed by the high proportion of male students, but sitting next to him was a bright and exceptionally cute girl named Kei Yamaba! Yusuke was planning to live in his uncle's house while he was away on an overseas assignment and take in a male roommate to earn rental income, but the person who actually moved in was his cute classmate, Kei Yamaba!? To make matters worse, the captain of the boxing club, who has a crush on Kei, finds out about their cohabitation...!