After miraculously surviving a freak helicopter accident, Hikari "Picasso" Haruma finds that he somehow has the power to help people through his art. He is helped by his friend Chiaki Yamamoto who was killed in the helicopter accident, but came back as an angel.

According to Chiaki, when the accident happened both she and Picasso died, but she begged God to save Picasso because of his wonderful talent, so Picasso survived the accident on condition that he saves other people. Basically when he sees someone in trouble, Picasso's able to draw a picture symbolizing the person's problem, and then enter that picture to see that person's hidden feelings and use that knowledge to help them in the real world.

(Picasso got his nickname because he wrote his name ヒカリ, hi-ka-ri, on his school shoes, but his リ looked like a ソ (so) and Chiaki called him "Hikaso" so he ended up being called Picasso. Even though he actually aspires to be like Da Vinci.)

(Source: MangaHelpers)