Yurika's strong point is seducing girls thru sex...
What if Yurika gets her claws on Sakurako before SakuKasu have sex for the first time?
Before Sakurako and Kasumi have sex? The way I see it, no way it could happen. These two are lovers since the day they first met, in chapter 1.
I've posted about this before, I think. When they first met, Sakurako was a baby lesbian who wasn't very clear about girl-on-girl nookie, and Kasumi was a more fledged young lesbian who had a better understanding of how sex works. Sakurako was lovestruck the moment she saw Kasumi; it was love at first sight, and Kasumi obviously realized it (it happens around her a lot). Then, when they were buying furniture and Sakurako boldly suggested sharing a one-person bed, Kasumi agreed... and at that point, without putting it into explicit words, the deal between them was sealed: they were going to be roommates but also sex friends, and that was because they both wanted it and were both okay with the other as a lesbian partner. Oh, Sakurako's reasons for wanting to sleep with Kasumi are evident, of course, she was already head over heels for Kasumi - but what about Kasumi's reasons, you may ask? Well, if I have to guess, Kasumi's reasons were: "She's cute in a puppy-like way, she seems to be a nice girl, she's bright and cheerful, and she clearly likes me. We are going to share a room for three years. I might as well sleep with her. It will make life easier and prevent dejection and angst and all those bothersome things I don't want to to deal with 'cause I'm lazier than Yasuda."
Then, in the three years that followed, Kasumi fell in love with Sakurako. Yes, because Sakurako is a good homemaker, reliable, hard-working, a smart woman with a good head on her shoulders, and, most important, someone who understands Kasumi perfectly and can take care of all her needs, pamper her and make her happy. Classic romantic fantasy. Only thing is, they were already lovers, and having sex all the time, when the falling-in-love happened. This wasn't how they did it in the olden times! Sigh, modernity, I swear. Anyway, you see my point: even in her high school days, if a gigolette went after Sakurako and tried to seduce her through sex, she would find that, oops, it doesn't work - Sakurako already has all her sex needs taken care of. By Kasumi. d( ͡° ͜ʖ ͡°)b