It is established here that three years have now passed since Soichiro's death, which means he died about six months before Kyoko became the manager at Maison Ikkoku.
Several panels in this story were printed "unflipped" in order for the baseball game to look right.
There is an incident here which was probably untranslatable. At the disco, when Godai is sitting next to Eriko, he's thinking about what Sakamoto just told him, and repeating to himself "even though she was only in high school, she did THAT... she did THAT... she did THAT..." The ford for "that" is "are", which in Godai's thoughts is written in katakana, that is to say, emphasized. Then, suddenly, Eriko looks up and exclaims "are!", and her "are" inserts itself at precisely the point where Godai's next "are" was supposed to go. This is the reason he looks at her with such an expression of guilt, because it is as if she had read his thoughts.
("Are", as an exclamation, can mean "There!", "Look!" or "Heavens!", according to my dictionary.)
Another bit that probably does not come across the way Takahashi intended is during the conversation between Kyoko and her friends. What has been translated as "those young studs aren't exactly known for their faithfulness" was originally something more along the lines of "you know, those young guys aren't all that innocent--they've had plenty of opportunities to fool around with girls in college." This, I think, is meant as foreshadowing for when Kyoko does run into Godai and Eriko at the end of the episode.
While I'm at it, it goes without saying that Sakamoto does not make the crack "Eri... short for airhead?" earlier in the episode. I'm not so sure about what he does say, though. On the surface, he seems to be just saying to Godai "So, her name's Eri!". To note that in that scene, in the original, Eriko's response to Jun is basically the same as Godai's response to Sakamoto: "wakatte ru wa yo", "I get it, I get it!".
The central misunderstanding is fundamentally untranslatable, but I think it could have been done a little better. What Godai's grandma says to Mitaka is not so much "thank you for looking after my grandchild" but "I believe my grandchild has been causing you trouble" or "is a source of trouble for you" ("o sewa ni natte masu soo de"). As is the case with other similar Japanese expressions (such as "sumimasen") this one has possible implications both of gratitude and of apology; Mitaka understands it as an overly courteous way to thank him for instructing Kyoko, whereas the grandma means it as a courteous way to apologize for the fact that he and Godai should be rivals.
What Mrs. Ichinose says afterwards in the original is "she insisted on meeting her grandchild's 'aite'". "aite" has the basic meaning of "the other party", and could be translated as "partner" (including a boyfriend or girlfriend) or "rival", depending on the context. Obviously, then, Ichinose means "rival" and Mitaka understands "boyfriend".
The somewhat bizarre title of this episode is a direct transliteration of the original, which was written in katakana and obviously meant to be "English". It is, in fact, the title of an old fifties song recorded by Rosemary Clooney (you can check it out here). It appears to have been recorded as well by a Japanese artist whose name I can't quite make out, but if you go here you can see her picture (and if your browser supports Japanese characters and you can read katakana, you'll see "Come on-a my house" as the second track on the song list ;-)).
The name of the pension is written in the original as "pension sarumon", with "pension" in Western letters and "sarumon" (which is certainly not the japanese word for "salmon") in hiragana (go figure).