Gokujou Onzoushi to "Kikan Gentei" Konzen Doukyo

The exciting prenuptial cohabitation begins with the sweet words, "I'll hold Ayaka in one month..."?
Ayaka has inherited her late grandfather's calligraphy class and lives a quiet life as a calligraphy teacher in the countryside. One day, she receives a phone call from her sister telling her that her first love Takashi, who was supposed to be engaged to her sister, is getting married to her. The confused Ayaka is told that Takashi, who has come from Tokyo, has proposed to live with Ayaka for a month! Ayaka is a shy girl. Takashi, who is always sweet on her whenever he gets a chance, but Ayaka is not so sure...?