First of all, I’d like to announce:

The Principal’s name is not Hanikama.

“Principal Hanikama” was a mishearing by a fansub translator, and so this misinformation has quickly spread throughout the English-speaking Hidamari fanbase with little doubt raised.

In S1EP03, gg-anon (subs used in FuktLogik’s DVD release) translated Sae’s line to Miyako as “Facial imitation of Principal Hanikama.”

The subtitles in question.

The line in Japanese was はにかむ校長の顔真似 // hanikamu kouchou no kao-mane // “An impersonation of the frustrated principal” [R1 DVD].

Admittedly, Sae does not speak very clearly when she says this and I can hear how easy it is to mistake the line. There’s just a mountain of evidence against it.  It’s not a name recognized in Japanese (check JMnedict). It has no basis in the manga (he gets an illustration inside the dust jacket of Japanese volume 3 but is labeled as nothing more than 校長 // kouchou // “principal”). Japanese posts and blogs quote the line‘s first word as “hanikamu“. And finally, an assortment of character bios on Japanese wikis and websites all reiterate the same thing: his name is unknown.

I ended up going through a few popular wikis and editing out all references to “Hanikama”. What I found most amusing was that in the cases where there was a field for the name in Japanese, the only thing in it would be 校長先生 // kouchou-sensei. Nothing suspicious about learning something from English subs then finding absolutely no references to it in Japanese, huh?

But is the Landlady’s name Tsumugi?

I don’t think so, though that is a nice name for her. First off, it has no basis in the manga. And just like the Principal, Japanese websites claim that her name is unknown. “Tsumugi” was printed on the cover of the yearbook the Landlady finds in her closet in S3EP10.

The top text on the cover is 卒業文集 // lit. “graduation anthology” with つむぎ/Tsumugi below. From my understanding, it is not unusual for schools in Japan to title their yearbooks. I found pictures of Japanese yearbooks with titles that translated into “Bonds”, “Threads”, “Ties”, “Companions”, etc.  Some were stylized in hiragana just like Tsumugi is here so that younger students can read it. “Tsumugi” translates to pongee (a type of thin woven cloth), which isn’t too far from the apparent naming theme. While I was Googling for this scene specifically I noticed Japanese posts would format “Tsumugi” as if it were a title, so it looks like that was the intended association for the viewer to make.