Restore (2003)

Main character used to live with his father and after his death is taken care of by father's aunt. He now has cousins to call him "Onii-chan", but he's not used to warm human relations. His childhood friend calls protagonist to join mechanic repair club, but he only agrees to join with motivation to repair old bike left to him by his father. As he repairs bike, gets a driving license and a part-time job, his heart gradually starts to melt, and spring of his life begins.