Many people who have had a traumatic brain injury (TBI) struggle to stay connected with others. They often lose friendships, become isolated, and have strained family relationships. This lack of social support is linked to worse physical and mental health, lower quality of life, and even a shorter lifespan. The investigators developed a program where a person with TBI and one close supporter work together with a therapist over 12 weekly sessions. They learn skills in communication, setting shared goals, supporting each other emotionally, and problem-solving, with occasional guidance from a peer mentor who has been through a similar experience. This study will determine whether the program is practical to deliver. We are conducting a pilot study with 30 pairs of participants to test whether sessions run smoothly, whether people show up and stay engaged, and whether participants find the program worthwhile. Based on what they learn, the investigators will refine this program before testing it on a larger scale. If successful, this could lead to a practical, low-risk intervention that improves the lives of people with TBI and the family members and friends who support them.