  Covariant quantization of multi-pronged open bosonic string junction is
studied beyond static analysis. Its excited states are described by a set of
ordinary bosons as well as some sets of twisted bosons on the world-sheet. The
system is characterized by a certain large algebra of twisted type which
includes a single Virasoro algebra as a subalgebra. By properly defining the
physical states, one can show that there are no ghosts in the Hilbert space.
