The first three panels have parody advertisements of the next round of video game console systems, the last of which had just been released when this comic was published.
sensei = teacher
Characters seem to run into each other by coincidence a lot in MT.
This is a function of one of the major core flaws with the Megatokyo story - too many main characters, too many storylines. It's an interesting exersize to keep everything in play, but its REALLY hard to keep the need to keep all of these characters and storylines in play without a feeling of deus ex machina in the way the encounters work.
For example - there's enough juice in the Piro Kimiko and Largo Erika storylines to run the entire comic. The storylines for Ping, Miho and Yuki (not to mention Seraphim which i backed off of a while ago) are also major storylines and have to be kept in play. This is the main reason that the MT story seems to crawl sometimes.