Eve no Onnatachi

In "The Christmas Eve Couple," by Matsufuji Junko, Aiko is unhappy in her marriage--her husband only married her to get ahead at work, and he's hardly ever home. Luckily, she has Kyouko, a woman she met online one lonely night. But when Aiko's husband suspects she's having an affair, their vision of a happy Christmas Eve together is looking less and less likely.