Morishita Hana (22) has a strong desire to get married but she doesn't even have a boyfriend yet. At an arranged date, she's reunited with her childhood friend Issei, a professional shogi player she hasn't seem for 10 years. Issei, who was kind and loving, is now so frightening that he's called "Demon Sergeant"!? However, when the two of them were alone during the arranged marriage meeting, there was a heart-pumping event that changed everything! “Would you like to date me with the intention of getting married?” Hana's desire for marriage has gotten out of control!