Both are based on true love stories of people who live in Fukuoka prefecture. Both involve overcoming hurdles which separate the respective couples. In Love Stories from Fukuoka 13, it's the fact that the female lead is deaf, while the male lead isn't. In Love Stories from Fukuoka 14, the the male lead wants to see the female lead perform her music live, but she must first overcome her fear of people.
Both have a husband who is very mean to his wife, leading to divorce. And both have a wife getting involved in a relationship with another man.
Both dramas' FL are in their thirties, and both are involved with younger men. Also, both FL's enjoy their own private time and freedom, and struggle over the the happiness and pain-free life achieved through being single versus the benefits of being in a relationship.