Hair styling device imparting an updo hairstyle when worn and a different curled or straightened hairstyle when removed

A hair styling device comprising:

• a headband wearable in a working position lying along a hairline of a user's head to span around a crown of the user's head with a front portion of the headband spanning generally across a forehead of the user's head and a rear portion of the headband spanning across a back of the user's head behind the ears thereof;
• wherein:
• the front portion of the headband comprises one of the following:
• an ornamental braid comprising a cluster of natural or synthetic hair configured in a braided pattern;
• or
• one or more jewelry chains;
• the rear portion of the headband comprises a bobble strand comprising a series of ball-shaped bobbles sequentially arranged along said strand, in an axial direction thereof denoted by a strand axis penetrating through said ball-shaped bobbles, in alternating fashion to a series of reduced-diameter necks that are interspersed between said ball-shaped bobbles in said axial direction and are also penetrated by said strand axis, among which each individual one of the ball-shaped bobbles and each individual one of the reduced diameter necks has a three-dimensionally convex shape, and the reduced diameter necks are of lesser diameter, measured radially of said strand axis, than said ball-shaped bobbles, whereby the alternating ball-shaped bobbles and reduced diameter necks are wearable to span in series across the back of the user's head, where the user's hair is able to be wrapped around the three dimensionally convex shape of said each individual one of the ball-shaped bobbles and said each individual one of the reduced-diameter necks at a rear of the hairline to impart a curling action that leaves behind a curled hairstyle on the user's hair when the headband is removed;
• and
• the three dimensionally convex shape of said each individual one of the ball-shaped bobbles and said each individual one of the reduced-diameter necks includes a full 360-degree circumferential convexity around said strand axis;
• and
• the bobble strand is further characterized by at least one of the following features:
• (a) the three-dimensionally convex shape of said each individual one of the reduced-diameter necks is externally ovoid or spherical;
• (b) the three-dimensionally convex shape of said each individual one of the ball-shaped bobbles and said each individual one of the reduced diameter necks also has an axial convexity along the strand axis, and the axial convexity of each of the reduced-diameter necks intersects with the axial convexities of a neighboring two of the ball-shaped bobbles where said reduced-diameter neck joins said neighboring two of the ball-shaped bobbles;
• and
• (c) the ball-shaped bobbles and the reduced diameter necks are embodied as integrally interconnected elements of a singular unitary body contained within a fabric cover of loose-fitting non-conforming relation to the singular unitary body.