BERKELEY – Charles Pierce really likes playing video games. He practices piano and violin. He used to study aikido, but lately he's been more interested in taking up fencing. Lately, however, the 13-year-old has mostly been hitting the books. Charles is the youngest transfer student this fall at the University of California, Berkeley, where he's now in his junior year. His 14-year-old sister, Mayumi, also transferred in this fall as a junior. Attending UC Berkeley is a bit of a family tradition: Their parents, Wincie Pierce and Qin Ma, met and married while they were students at UC Berkeley in...