I don't care what anyone says, I would watch a thousand seasons of this goddamned show.
Sakaki wishing Mayoi a happy new years just in case she didn't get back in time was pretty funny. The Closet of Woe was probably my favorite part; Tsumiki may be able to fend off most of Mayoi's foolishness, but invoking Io is her kryptonite. Whenever Io tosses out a cool line like the one in the Santa suit, I keep expecting it to reveal that it's a Tsumiki delusion, ala Eu from KoreZon.
Tsumiki getting in line with a cake on her head for Io head-pats...
The bear suit face-plates were tremendous. It's "scary" but not for the reasons Mayoi intended.
"This will be our little secret." S-stop it, Io... don't make me love you.