Hyper Baby

From Forbidden Garden:
Maria is a high school student, and is on her way to visit her sister in the hospital, who has just given birth to a baby boy. Things soon start to get strange when Maria sees a unusual (but extremely cute) boy at the hospital who is very interested in Maria’s new nephew. The boy always seems to be hanging around, and only Maria seems to be able to see him! Is he a ghost? A demon? Why is Maria seeing him?
As if this wasn’t odd enough, Maria soon meets another (extremely hot) guy in the lobby of the hospital. He is tall and rather suave-looking, and has a bouquet of roses. He is also interested in the birth of Maria’s nephew, and gives Maria the flowers. Maria is obviously confused about all this attention little Masaki (her nephew) is getting. Who are these strange guys?!
The first guy she saw appears again later at Maria’s own house, in Masaki’s nursery. Maria is shocked to see the boy materialize right out of baby Masaki’s body! What is going on?! Is it a dream?! Why is this boy appearing from within the baby? He is begging Maria to protect her nephew, but he doesn’t say from what. He also wants her to meet someone named Ichirou KOUZUKI. Who is that? Is he that other guy at the hospital? Why is everyone so interested in Maria’s nephew?