Say You'll Be Mine, Starving Succubus

From Renta:

At first glance, bad boy Osamu is about as about as opposite to class president Ikko as they come. Despite their differences, Osamu has a soft spot for Ikko and always watches over him from the shadows. One day, after rescuing Ikko from a group of bullies, Osamu mysteriously falls fast asleep. In his dreams, Osamu encounters Ikko, but there's something very different about the boy he's been crushing on... A school love comedy between a delinquent and a starving demon in disguise.