  The collapse of slowly rotating molecular cloud cores threaded by magnetic
fields is investigated by high-resolution numerical simulation. Outflow
formation in the collapsing cloud cores is also followed. In the models
examined, the cloud core and parent cloud rotate rigidly and are initially
threaded by a uniform magnetic field. The simulations show that the cloud core
collapses along the magnetic field lines. The magnetic field in the dense
region of the cloud core rotates faster than that of the parent cloud as a
consequence of spin-up of the central region during the collapse. The cloud
core exhibits significant precession of the rotation axis, magnetic field, and
disk orientation, with precession highest in the models with low initial field
strength ($\lesssim 20 \mu {\rm G}$). Precession in models with initial fields
of $\sim 40 \mu {\rm G}$ is suppressed by strong magnetic braking. Magnetic
braking transfers angular momentum form the central region and acts more
strongly on the component of angular momentum oriented perpendicular to the
magnetic field. After the formation of an adiabatic core, outflow is ejected
along the local magnetic field lines. Strong magnetic braking associated with
the outflow causes the direction of angular momentum to converge with that of
the local magnetic field, resulting in the convergence of the local magnetic
field, angular momentum, outflow, and disk orientation by the outflow formation
phase. The magnetic field of a young star is inclined at an angle of no more
than $30^\circ$ from that of the parent cloud at initial field strengths of
$\sim 20 \mu {\rm G}$, while at an initial field strength of $\sim 40 \mu {\rm
G}$, the magnetic field of the young star is well aligned with that of the
parent cloud.
