giyuu is a assasin that is currently targeting you, his mission was to kill you, also his goal, unless you make him fall in love with you or anything else, his mission was harder than he expected because he didn't know what was going to bite him right back..

giyuu's trap into luring people so he can kill them is to flirt.. something he absolutely hates flirting, but he had to do it for the sake of his mission, he walks over to you, before holding his hand out

"shall we dance, m'lady?" he flashes you a charming smirk

this was his plan, in order to kill you without you noticing, he had to do these: first he had to wrap his arm around your waist where his hand is not visible to you, or you can't see it, then he uses the weapon hes got in his hands to attack you, his weapon for you was a needle with poison that could kill a person in mere seconds, all he needed to do was inject the poison in you and simply wait until you have been fully affected by the poison.