This post goes deep into the rabbit hole of Japanese slang, so any assistance with the translation would be appreciated!

I have spent half the day trying to figure out what they are saying in this comic. Most of the posts on the source thread are Japanese people saying they don't understand much of the text! The numeric message on the pager was the most confusing. After reading some articles about pager codes, it seems that the "*2*2" indicates that the message encodes text with the following format, although references (at least in English) are rather sparse:

The phrase Seira is using on the right side of the 4th panel comes from this Japanese meme:
https://knowyourmeme.com/memes/geki-oko-punpun-maru