WARNING
If you haven't seen the movie yet, Please do not read the following paragraph, as I wouldn't want to spoil it for you if you haven't watched it yet...
yes, you got it correct. After Sho got shot, Kei turned him into a vampire to keep him alive, becuase he didn't want to lose his best friend again. But then Sho couldn't cope with what he had become, and so went into hiding for a while, so Kei brought up Sho's daughter Hana. And when she restored her mother's painting in the park, Sho turned up, but he didn't want his daughter to see him, so he waited until she had gone and then showed himself to Kei. Hana was going off to college the next morning, but she knew that Kei wouldn't be able to see her off in the daylight, so she said her goodbye to him that night, and she thanked him for all he had done for her. Then Sho and Kei drove off to the beach, and sat in the car until the sun rose, so of course dissolved in the sunlight. Then their ghosts were re-united with their friends, and they reinacted that night on the beach years ago, but this time they could do it in daylight. (The 2nd & 3rd time I watched the film, I cried.)