On 30 January 1996 this comet was discovered by Yuji Hyakutake for whom it was named. Officially the comet is known both as Hyakutake and C/1996 B2.
Only the astronomers’ professional organization, the International Astronomical Union (IAU) can decide on names, and there are strict rules surrounding the naming of celestial bodies. For example, comets are always named after their discovered. In the case of asteroids, the discoverer is entitled to suggest a name but it must be approved by a committee of the IAU. These days, most stars are merely given a catalogue number which usually contains a set of celestial coordinates indicating the body’s position in the sky.