Gvavaya Anime Cosplay Iguro Obanai Cosplay Costume Demon Killer Corps Uniform

I received the two cosplays in record time and I really appreciated it.
Tried them on immediately and they were very comfortable, I had to slightly widen the opening for the buttons on the jackets but otherwise they were perfect.
But I didn't understand what the white laces are for in Obanai Iguro's costume.
Ah, the gifts were wonderful! Thank u so much!