Update to "Kohlberg's Stages of Moral Development and Iino Miko's 'Childish Justice'"
SatorinI wrote a way-too-long essay about Miko here last August when Chapter 233 was published; this is a (much shorter) update to that essay.
After an unexpectedly quick and anticlimactic resolution to the Osaragi arc in 234, we see that Miko has taken Kaguya's advice and successfully smoothed things out with Osaragi, and is also inching ever closer to Ishigami with her newfound lack of tatemae like in chapter 246. But for Miko's personal development, a really important moment came in Chapter 253, where Miko shows that she has finally managed to pursue a line of action with a post-conventional level of reasoning behind it.
From my previous essay:
People operating on [the post-conventional] level perceive actions through the lens of ethical principles, and may disobey rules because they are inconsistent with them.
Miko has been shown to consistently be stuck below this level as stated in the main essay, but in this chapter, she has shown true character development in that she is now willing to do actions outside of what society accepts as "legal" for a higher moral standard:
the higher moral standard being to protect those that she thinks deserves protection. As the daughter of a judge, and as a person who looks up to her parents very much, she's now willing to blackmail an evil person to protect the good, even if it means that she goes against society's laws preventing her from doing so — all because she now has a higher ideal to perceive the world through.
Miko-chan's all grown up now.