Yang tries to talk to Blake more than once, and Blake ignores her both times. If she's even ignoring her partner things must be very bad, so Weiss has reluctantly formed some kind of unofficial alliance, the "let's go find out what's wrong with Blake" club. It's purely because the team is self-destructing now that she won't even tell them what's wrong, not because Weiss and Yang actually enjoy working together.
"All right, so Sun was a dead end," Weiss says dispiritedly, scanning the depressingly short checklist of people Blake might consider friends. "How about Ruby?"
"I mean, she might know, but –" Yang lowers her voice even though they're alone in a practice room with the door locked – "you know Ruby's not too good with people. Even if Blake talked to her about something she might be oblivious."
"I'll talk to her anyway," Weiss says firmly. "That leaves you to deal with Team JNPR."
"Are you sure we shouldn't just try to talk to Blake?" Yang asks.
"I'm sure," Weiss says firmly. "I tried."
Weiss bought Blake chocolate from the finest confectioner on Remnant and left it on her desk with a nice note, in hopes that Blake would warm up to her slightly. Ten minutes later, Weiss showed up again to find Ruby contentedly devouring the chocolate ("Blake gave it to me, wasn't that nice of her?"), and Blake and the note nowhere to be seen.
Yang gives another despairing sigh.
"Last time she got like this talking to her actually helped, you know. Maybe I should try."
"And what could you achieve that I couldn't? I've been trained in negotiation since birth, you know."
"Negotiation? Weiss, this isn't a business deal. Blake's a person, and I'm her friend."
"Are you suggesting that I'm not her friend?" Weiss snaps.
"Yeah, I am! Maybe if you were really Blake's friend, you would've been there for her!"
That hits Weiss a little harder than she cares to admit. She knows she's not the best at getting along with people sometimes, but she tries her best.
"You haven't contributed a single valuable insight to this meeting!" she shouts.
"Well, if I'm so useless, then I'll get out of your way." Yang throws open the door to the practice room. "Good luck trying to find the problem with Blake by avoiding her."
Well, that's a – minor setback.
Weiss covers up a sniffle and closes her notebook. She'll go talk to Ruby, and that'll help. With Weiss's investigation, that is. Not with making Weiss feel better, because Weiss doesn't need someone else to make her feel better and if she did it wouldn't be Ruby Rose. Nope.
Ruby is in their room, poking around in her scythe's innards with a screwdriver. She looks up, says "Hi, Weiss!" in that infuriatingly cheerful voice, and looks down again.
"Hi," Weiss says. It's the first time in a while she's deigned to give Ruby such an informal greeting. "Can we talk?"
Ruby slowly spins around in her chair, face suddenly serious and worried.
"What is it?"
"Blake's been acting weird recently," Weiss starts.
"Oh, no, I don't think I'm supposed to tell you about that," Ruby says immediately. "Unless, of course, you were just making an observation and not planning to interrogate me, in which case forget everything I said."
Weiss is a master of diplomacy. She can do this.
"Are you sure you couldn't tell your beloved teammate?"
Ruby blushes a little.
"Beloved? I mean, you're nice sometimes and all, but I'm not really –"
"I meant platonic love," Weiss interrupts. "Obviously. But surely whatever Blake's problem is, we can solve it together, maybe? As friends?"
"Best friends?"
"Sure." Weiss is prepared to make concessions for the sake of the investigation. This has nothing to do with her actual feelings.
"Besties!" Ruby wraps Weiss up in a bone-crushing hug.
It takes far too long to pry Ruby off of her and insist that she'll buy cookies to "commemorate this momentous occasion in our friendship" later, but eventually they're settled back down and Weiss has her notebook open on her lap, ready to take down every word Ruby says and dissect it later.
"Blake and Yang kissed a few nights ago," Ruby says quickly. "And, well, Blake has feelings, Yang doesn't, and so things are awkward. That's all I know."
Weiss pauses halfway through scrawling the sentence down.
"But why would Blake be upset at me, when I didn't – oh, no."
"What's wrong?" Ruby asks, but Weiss tears out of the room with a shouted excuse about returning a library book. Once she's out of the way of the areas her team members frequent, and doesn't have a chance of being interrupted, she starts walking blindly, muttering. She'd like to shout something that adequately encapsulates how she feels, but there are far too many vague thoughts in her brain. She tries to form an organized list.
Yang's apparently made it her life's work to seduce her team members and ruin them.
That's not the most relevant piece of information, regardless of how irritating it is.
Blake has feelings for Yang and is upset at Weiss. She knows about the event, and although Blake isn't one for gossip, she at least told Sun, who has probably spread the news all over the school, and she wouldn't put it past Blake to start a rumor for the sake of revenge.
At least Weiss more or less knows what's going on now. Of course, that doesn't help her much, unless she can magically inform the entire student body that there's nothing going on with her and Yang, thank you very much.
Weiss is used to being blamed for things, but usually she at least deserves it a little. This is just ridiculous.
With a little scream of rage, Weiss drop-kicks her notebook at the opposite wall, where it smacks the cork bulletin board, sending a flyer informing the students of the latest change to the Board Game Club's schedule fluttering to the ground.
That's it.
…
Two hours of work later, Weiss has the posters printed out. They're obscenely large and flashy, but it's critical that the entire student body gets the message.
Attention Beacon Students!
Yang Xiao Long and Weiss Schnee are not dating! They never have been and they never will be! Speculation is not appreciated!
If that won't put an end to any rumors about Weiss once and for all, she doesn't know what will.