Why the random katakana in 「すみっコぐらし」? Some of you may be familiar with the San-X line of characters called . The shtick is that they're timid and like "living () in the corner ()" I know katakana is frequently used for emphasis, but what is the wordplay intended by writing just the single syllable in in katakana? !enter image description here

What is a "corner" shaped like? ;)

In addition to drawing your attention by being unusual, it's visually appropriate for the meaning. I'd suggest it's as much/more a graphic design choice than any linguistic emphasis.