Kibun wa Pastel Touch

Main character is count Dracula and he proposes to a Japanese girl Umi. Response is put on hold till Dracula picks her up in the daytime. Three months later he visits her school as a male student to charm girls with magic and get Umi whereabouts from them.

There are a lot of bad endings, so frequent saving is a must. Otherwise it's quite a pleasant slightly erotic bakage.