Grommet

A grommet comprising a tubular portion, wherein

• the tubular portion extends along a first direction, and has a tip end and a base end located opposite to the tip end in the first direction,
• the tubular portion is provided with a through hole extending in the first direction and opening at the tip end and the base end, and
• when the tubular portion is viewed from the tip end along the first direction,
• a first opening edge has a first portion, the first opening edge being an opening edge of the through hole at the tip end,
• the first portion has a first end and a second end, the first end being an intersection point of a first line and the first opening edge, the first line passing through a center of the through hole and along a second direction orthogonal to the first direction, the second end being an intersection point of a second line and the first opening edge, the second line passing through the center and along a third direction orthogonal to the first direction and the second direction,
• there are a first position and a second position on the first portion, the second position being further away from the first end than the first position in the third direction, and
• a slope of a tangent of the first portion increases from the first end toward the first position, and decreases from the first position toward the second position.