The 3 Roses.

From left: Rosa Gigantea, Satou Sei. Rosa Foetida, Torii Eriko. Rosa Chinesis, Mizuno Youko

Sei gets more focus than the other two roses, but they do get some limelight. These 3 are presented as figures with strong personalities and abilities they command such a high respect from their imoutos, it's ridiculous. -_-b but it's funny too at the same time. Eriko seems to be so capable at all things that she is usually apathetic abt most things. Only when she sees something that seems interesting that she becomes ... enthusiastic. Youko is like the most elite student. Manipulative and gentle at the same time, just her courage to take Sachiko as her petite soeur deserves some applause. The other 2 roses refer to her as a meddler... =D that's y they have such a grand reason to dump all the work onto her... haha. Sei is more flirtatious and straight-forward, but at the same time, closed up too~ On first glance she may seem closer to Youko, but actually Eriko and her go way back... I think Eriko kinda like tossed the hot potato to Youko when she volunteered herself by "meddling". But they do care abt each other. They just don't show it, and it's fascinating that all 3 of them understand each other so well, that they're comfortable with their distance apart.