I followed up on TERRYNAUT's lead and found the Korean mangwa story GIRL IN MY DREAM on the TGCOMICS website. A well-paced easily understood story about a teen-age boy who falls in love with a girl classmate. On their first date the girl is killed, hit by a bus, and the boy injured. After waking up in the hospital he begins a slow metamorphosis into a teenage girl without apparent cause and much to his dislike. At night he is visited by a dream character who he calls Yuna and with whom he has a seemingly loving relationship - and who may or may not have anything to do with the changes.