I'll Have My First Time Within A Week!? Manga

“You will lose your virginity within a week!” A friend took me to see a fortune-teller, who then made this shocking declaration! If I meet a boy with a heart-shaped mark on his body today, he will be the one I’ll have my first time with! But I don’t have a boyfriend, and I’ve never even talked to my crush in private before… Or so I was thinking, when I ran into him, my senior from college, and got invited to a drinking party at his house… Is HE the man of my destiny…? However, my mischievous childhood friend and my friendly junior also turned out to be there… Which of these three boys will I end up having sex with…!?