Megami No Libra

Yuuki Tsumire was raised by her single mother, who always told her to keep smiling, no matter what hardships she endured. The two of them were a family, until Tsumire's mother died from illness. Tsumire soon learned that she had a family she knew nothing about: a cold, rich family that disowned her kindhearted mother when she became pregnant. Tsumire now must go live with this family, even though none of them seem to want her there. She doesn't have to switch schools, so she at least has her friends to help her through this difficult time. However, she doesn't have the heart to confide in her friends with even more problems, so she tries to keep it bottled up inside. To her surprise, the Yuuki family lawyer, a young man named Hino, soon becomes her emotional support in this difficult situation. However, Tsumire's reactions to him might mean that she wishes he were something more...
Thanks go to tethysdust for the summary.