The University of Berkeley hosts a unique pair of college students, Mayumi and Charles Pierce.

The two are juniors at the University of California, Berkeley, at an age when most kids are nervous about starting high school. Mayumi is 14; her younger brother 13.

With three years of community college under their belts, they are now taking classes like philosophy and biochemistry.

Mayumi says they like calculus, but it's hard to get to class on time because the campus is so big.