Fastener Stringer and Slide Fastener

A fastener stringer comprising:

• a fastener tape that includes one or more weft threads and a plurality of warp threads, the fastener tape having a first tape-surface and a second tape-surface;
• and
• a coil-shaped element that is provided onto the fastener tape so as to appear at a side of the first tape-surface of the fastener tape, the coil-shaped element including a series of unit structures, each unit structure including:
• a first leg that extends along the weft thread;
• a second leg arranged farther away from the weft thread than the first leg;
• an engaging head that couples the first leg and the second leg at a position outwardly of fastener tape;
• and
• a return portion that couples the first leg and a second leg of an adjacent unit structure at a position inwardly of fastener tape, wherein
• the plurality of warp threads includes total N adjacent tightening threads each repeats crossing over N second legs at a side of the first tape-surface and crossing over the weft thread at a side of the second tape-surface so as to tighten the coil-shaped element to the weft thread, said N indicating a natural number equal to or greater than 2, wherein
• each tightening thread includes an exposed portion that crosses over the weft thread between the first legs arranged adjacent in a length direction of the fastener tape and that is exposed at a side of the second tape-surface, and wherein
• as the total N adjacent tightening threads extend, the respective exposed portions of the tightening threads appear at a side of the second tape-surface one-by-one alternately or one-by-one sequentially.