Naruko has neck-length reddish-brown hair and dark brown eyes. She's roughly the same height as Tsuda, maybe slightly taller, with a noticeably full figure she's quite proud of—though apparently not quite as impressive as Aria's.
As a teacher, she doesn't wear a uniform and sticks to the same outfit: a purple long-sleeved shirt with white accents and collar, fitted grey pants, a loose belt usually sitting at her hips, and a single blue bracelet on her left wrist.
She's attractive enough, but her relentless perverted streak is a serious turnoff for most people. Tsuda won't let her get away with anything, and even the Beach Playboy bailed when he realized how aggressively she'd pursue him.
Naruko is genuinely one of the most perverted characters in the series—arguably even more so than Aria or Shino. She's got multiple lovers, actively hunts for younger guys (including students), and has zero shame discussing sex, bondage, outdoor encounters, or whatever else is on her mind. She's portrayed as pretty useless at actually teaching, which is apparently why they stuck her in the Student Council—the members are so competent they can cover for her incompetence.
That said, there's more to her than the gag. She genuinely worries about hitting 25 without being married, something she brings up constantly, and there are hints she actually cares about kids. More importantly, she's a genuinely capable teacher when it matters—she took charge without hesitation when Suzu got separated from the group during a school trip to Osaka, proving she can handle real responsibility when an emergency hits.
Content compiled by AnimeList.moe from publicly available sources.