Details: After Logan's mother's death, his father, Clay, blocked him out and Logan was entrusted to his maternal grandparents. Logan thinks his father left because he was to hurt by Sara's death and he still hoped that one day his father would come back.
Logan met Clay in a psychiatric home and was unaware that Clay was his father. Clay and Logan formed a close bond, and soon after Clay remembered that Logan is his son. He spoke to Logan about it and asked him if he could be in his life. Logan left the room and said no. So Clay went in Sam and Lil's home and asked Logan again. Logan accepted and moved in with his father. Later he formed a strong father-son bond.
Details: Sara was Logan's mother but she was died when her son was a baby. Nevertheless Sara would love very much her son and would be very sweet and kind with him.
Logan hasn't memories of Sara but she is still very present in his spirit and loves her very much.
Details: Quinn is Logan's father's new wife and so Logan's stepmother. When Logan moved in his father and Quinn, Quinn helped Logan with his Ocean fear. Later they camp together and duing Clay's proposal to Quinn, Logan gave his Green Lantern Ring to them. Eventually he called Quinn 'mom' and she decided to adopt him.
Details: Haley is Quinn's younger sister and so Logan's adoptive aunt. It's presmuly that she and Logan are in good terms because Haley is very close to Clay and Quinn. She would be happy to have a close nephew because her biological nephews and nieces live out Tree Hill.
Details: Due to Clay and Nathan's relationship also well as Haley and Quinn's the two families were very close and spent a lot of time together making it likely Nathan and Logan would have gotten on well.
Relationship: Adoptive first cousin (via Nathan and Haley)
Details: Jamie is Quinn's nephew and Logan's adoptive cousin. Both seem close, they threw watter bombs on Logan's parents and Jamie's godmother and Julian. Later Logan is see at Jamie's match and encourages him.