Shoujo Sect

Both are centered around yuri, and the fact that the main girl isn't assumed to be a lesbian. Both main girls try to help the troubled people around them before exploring their own self. The destined lover in the series both act troubled, ignore the school rules, and have their own self confidence that may be seen as arrogance. Shoujo Sect has more hentai-like scenes BUT are not terribly explicit compared to an actual hentai. Lastly, both series seem to have the same type of elegance and classical piano pieces played throughout the series. 

Both shows have a strong vein of past love, unrequited love, and sadness. Their main settings are girls-only boarding schools. Many similar character types exist. I'd go into details, but that would spoil lots of things. While the main difference between them is both length and sexuality (Shojo Sect is a 3-ep OVA hentai while Strawberry Panic is a 26-ep anime with mild-to-moderate ecchi), they're both worth a watch. 

If you liked watching Shoujo Sect, which is a yuri hentai, you might like this one too! Its also yuri hentai and so cute! 8D 

These two series are yuri hentai with a lot of focus on the romance and characters.