The personality type "Uchi" was a localization error made by an editor here on the wiki a while back. There are no 'official' personality type names written internally into the game itself, so cranky, peppy, normal etc are all fan-made titles made by the wiki, where they then spread to be used within the English speaking community and other wikis such as Nookipedia. The name 'uchi' was a mistranslation and has no real English meaning nor does it entirely make sense in Japanese. Its derived from the fact that in the Japanese release of New Leaf the sisterly villagers use the first-person pronoun "uchi", which is effectively the same as naming the personality type "me/I" - it makes no sense. The real Japanese term to describe their personality is 'aneki' which means along the lines of big sis, sister, etc and is best translated into "sisterly" in English. The decision was made to rename the page from uchi to sisterly as with the release of New Horizons, there would be many new players who would be exposed to the game for the first time.