Gojo being too distracted to realize he used his personal account to reply to the author and triggering an investigation by Reddit to discover his connection to Marin and then dox them.
But that's some other arc for later, now we get fluff after ... A lot of miscommunication chapters.
As wholesome this chapter is, I fear Gojo has painted a giant target on his back with that reply to Shiba-sensei's comment. Now the agencies that are looking for that "mysterious cosplayer" have an attack vector.
You know what would be peak? The ending is Marin and Gojo have seggs while Marin wears each of the cosplay that Gojo made for her, and then ends up with just Marin herself in a cute lingerie. That would be so peak
I am very intrigued by where the “thank you” reply is going to lead. People were buzzing about who the mysterious cosplayer could be, and Gojo basically put up a neon sign with big glowing arrows