The source for Sayu's segment on False's show was the video: "【NEW STARDEW UPDATE】Starting a new file because of the BIG UPDATE! w/renniesaurus" at
6:26:30.
She would later follow up on a Twitch-only stream titled "chatting a bit then back to #1 BIGGEST BOX MOUNTAIN EVER", discussing it at
14:36.
As for why this is happening, there's a clip of something Sayu said during her October subathon, just before Matara's debut. The title is "Sayu Talks About Zaion's Time in Nijisanji - Mentions Kotoka & Finana". There, at
4:26, she talked about how Zaion's last message to people before she left was that they were worth more than they thought they were, then specifically mentioning a time when Nina was crying to her in a voice call about how she felt like she was nothing without Niji.
And in an interview with FalseEyeD, "FalseEyeD Interviews Sayu Sincronisity", found on this very channel (plug plug), at
28:18 False brings this up, and Sayu immediately follows up with mentioning how she's blocked (and basically confirms it in chat at
30:38) but still says how she's sorry.
So it's pretty clear that Mata likely didn't appreciate how Sayu told her entire audience about this, especially just a few days before her debut when she was feeling very nervous and emotional.
As for the question "Why hasn't Mata unblocked her?", I think a quote from Mata's stream on December 10, 2023 is relevant (Unfortunately, it seems to have not been uploaded to her VODs channel, but I have a recording of the relevant segment on my hard drive). In it, she discusses how she ended a friendship with someone she said she was friends with before her time in Nijisanji because they were talking badly about her recently
"I tend to buy a lot of gifts. The people that are close in my life, I give all my time to them. I help them, I am there for them, I check up on them, I'm present, I'm available, I have a lot of time. If somebody loses that trust and friendship with me, now I have more time for the people that really matter. So if I lose a friendship because I find out that, you know, somebody has been talking shit or there's jealousy or anything, good! More time for other people, more time for the people that matter.
"And another quote from the same stream:"There's this phrase and it's so corny but he makes so much sense, I hate how much this phrase makes sense. It's like "losers focus on winners, winners focus on winning" ...I don't have time to hate! I gotta stream! I gotta react to a Bricky video! (laugh). I don't have time to hate! I gotta hang out with my girlies in VShojo! But seriously, I, I just don't have time to hate! Life is long, you know, i gotta go to the gym, I gotta make my food, life is good! If you got time to hate you're not making time for other things in your life. Seriously, hating, hating is a full time job, I really do think so. I really think, like, hating is a full time--,and I'm talking serious hating right, like, I'm not an angel, I dislike some people.I dislike a few people here and there you know, it's normal. People can rub you the wrong way and you can just dislike them that happens to everybody, even to me (laugh).But even I don't put a lot of time into the hate, i just ignore."
And as someone who watches her streams a lot, this isn't just talk. This very much lines up with how she actually behaves. So while I think it's unfortunate that these two aren't on good terms now, I don't think Sayu is owed forgiveness from her, even if I personally am willing to forgive Sayu and continue to watch her.
And wit that in mind, it's pretty obvious why Sayu is never getting into VShojo. After losing Vei, Silvervale, Nyanners, and Nazuna, I'm convinced that the VShojo talents and members only want new members if they're committed to agency for the long-haul, and aren't likely to cause tensions with existing members. Especially since members keep their IP when they join/leave.
And as a big VShojo fan, PLEASE stop asking people to join VShojo! Chances are good that they've already considered it. They don't need you to remind them. And there's nothing wrong with being an indie.