Marine will perform with that person from the teigegki in a commemorative 3D live performance.

It could be Chisataro from Jump Broadcasting Station, Milk, Tsuna Misa, Sammy, Yuna, or...

Shiraka meme material
[GB] fubuki fox memes summary + usage examples [#shirakameme]
https://www.youtube.com/watch?v=YIHd1pctXvM

Source of the content
Luxury guests too!! 【Hololive/Takarajima Marin】#Takarajima Marin Birthday Celebration 2025
https://www.youtube.com/watch?v=1WbyakjUmsI

That person's blog
http://chisa-club.cocolog-nifty.com/blog/