Following the loss of their parents, Ryo and his sister Akane lead a relatively content life. However, their world is thrown into chaos by a secret government initiative aimed at combating Japan's declining birth rates. Against his will, Ryo is thrust into an arranged marriage with Shizuka, a willing participant in the program. Despite his resistance, Shizuka embraces her role as his fiancée, much to Ryo's dismay. Surrounded by intrusive bodyguards, meddlesome friends, and a zealous betrothed, Ryo's once predictable life takes a dramatic and unexpected turn.