Please ♥♥♥♥ Me!, Namaiki: Kissuisou e Youkoso! The Animation Recommendations
The two OVAs both feature a protagonist who comes across a mysterious white haired girl with hime fringe and powers that help him get laid, as well as romance said white-haired girl.
While Namaiki is vanilla, Please ♥♥♥♥ Me! is obviously a bit darker.