
Spoiler
He's the fiancee of that blue haired person at the end of the chapter.
He was the one who was sending those gifts to mielle because he thought she was aria.
According to the novel, he will appear in the party of that blue haired bitch (Oscar's sister) just to see if aria was mielle. Everything changes when that happens.
The web toon seems a little different compared to the novel but all the important events are there.

so this asher guy is the crown prince and he is so fucking madly in love with aria like he would sell his soul for the devil for her and he is the one whose sending all the gifts for aria but his servant mistook milelle for aria so she took all of them, and the crown prince is the blue haired bitch that appeared in the last ch so he will go to her BD party and he will find milelle there so he will go to her bec he thinks she's aria and when he'll find out that she is not OMG he will teat her so coldy that she will shever and cry (was so happy at this part ) and the blue haired bitch will think that milelle have some kind of relationship with the prince and will be suspicious of her, ohhhh and milelle in the next ch will literally ask her to marry her bro
there is more but I don't know if you like the way I describe things and am pretty sure that I wrote milelle's name wrong so sorry about that, and if you want me to continue please tell me bec I will gladly do (づ ̄ ³ ̄)づ

you are so welcome, so the blue haired bitch will agree on the engagement of her bro and milelle and they will announce it in a grand party as a surprise and aria will be so pissed of after that asher's servant will know he made a mistake and will start to treat aria good and will bring her tulips every time which Is the symbol of the kingdom
someone please ask me for spoilers I reeeeally want to spoil it for someone (≧∀≦)