Minami logic is the name ascribed to a type of unusual reasoning characteristic to the Minami Sisters, primarily Kana and Chiaki, but also Haruka to some degree. It is often illogical, without common sense, and occasionally borderline insane, but the key trait that distinguishes it from mere bad thinking, which is used at least once by almost every character, is that it always makes a certain amount of crazy sense. That doesn't stop it from being crazy. They are often unaware how illogical their line of thinking is, but occasionally use it deliberately, as a tool to manipulate others. It is also hilarious, of course.
An exhaustive accounting of all examples would be an abbreviation of nearly the entire series, so it is likely best to stick to a few of the best examples.
- In Minami-ke Episode 01#Segment Four, Chiaki convinces Kana to go to school without breakfast with a convoluted argument that boils down to "They have food there, for lunch". Chiaki is consciously exploiting Kana's susceptibility to Minami Logic, since she surely realizes that the school having food available for lunch is irrelevant to how hungry one will be at school without breakfast.
- In Minami-ke Episode 01#Segment Five (Minami-ke Chapter 002), Chiaki convinces Kana that a love letter from Fujioka is, in fact, a letter of challenge from the local Banchou. While it initially seems likely that Chiaki has once again deliberately misled her, it later becomes clear that she fully believes her own explanation.
- In Minami-ke Episode 05#Segment Two, Haruka mysteriously accedes to Chiaki being hung up as a Teru teru bozu.
- In Minami-ke Episode 06#Segment Four, Kana's strategy for Makoto to sneak into the household under Chiaki's nose is for him to cross-dress as Mako-chan, a plan which, unbelievably, succeeds beyond anyone's expectations.
- It underlies Chiaki's decision in Minami-ke Episode 10#Segment One to designate Touma as her little brother, as part of her surrogate family theory.
- In Minami-ke: Okawari Episode 03#Segment Three, Kana decides that the best way for her to show hospitality to Chiaki's friends is to offer them milk as they leave the bath.
- Minami-ke: Okaeri Episode 05#Segment Two, pictured above, is one of the shining examples of Minami Logic, with almost every one of Chiaki's decisions being highly questionable, yet always carrying a kernel of logic in the middle.
- In Minami-ke: Okaeri Episode 11#Segment Two, Kana draws upon wordplay between "hospitality" and "warmth" to conclude that the proper way to show hospitality to Fujioka, Riko, and Keiko is to invite them to use bathwater heavily laced with chili peppers. Fortunately for the others, however, none of them dare to use it, never even looking at it, and only Kana is hoist by her petard.