Gisou Kon: Kono Dekiai, Honmono to Kanchigai Shisou desu

After losing her parents at a young age, Yae Sachiyama was taken in by her uncle. Since then, she's been living under his roof while he and his wife drain her of both freedom and money. The only place she can truly relax is at her workplace, Kuga Industries. There, she quietly harbors feelings for the CEO, Tomomitsu. Because of her difficult home life, however, she can't bring herself to tell him. Her feelings for Tomomitsu only grow stronger with each small act of kindness he shows her. But one day, when Yae returns home from work, her cousin's attitude suddenly takes a strange turn and she finds herself pushed further into a corner... The story of a sweet but complicated marriage, born from a life of mistreatment. (Source: MangaPlaza)