Yangire (
ヤンギレ)
Yangire is referring to characters who snap all of a sudden out of jealousy or irritation or something similar. It comes from the words
yanderu (病んでる - being sick from something) and kire/
gire (切れ - to cut, slice, "to snap"; 逆ギレ - being angry at someone who would normally be angry at you).
Most yangire references include
Takamachi Nanoha from
Mahou Shoujo Lyrical Nanoha StrikerS, specifically the development in its 8th episode when Nanoha has a mock battle against Teana and Subaru. When the two girls almost outsmart her during battle, she snaps, goes all freakishly quiet and gives a fair beating to Teana.
Yangire most likely stems from
yandere, but yandere
refers specifically to heroines who are in love with the main character, but become mentally sick or unstable due to certain developments in the story. Still, the term is fairly new and not as popular as tsundere or yandere, but recently a few
high-profile Japanese weblogs have started pimping the new term. Hopefully, Nanoha might be snapping some more, now that the 18th episode of
Mahou Shoujo Lyrical Nanoha StrikerS has a new opening sequence portraying Subaru as the main character.
(Image taken from AkibaBlog.net)