软妹轰炸机
[ruăn mèi hōng zhà jī]
It may seem puzzling at first, but it has a clear image behind it: 'Ruannmei zhamdanji'. Literally translated, it refers to a cute and seemingly weak - looking girl ('ruan' stands for soft here) yet she's a bomber with unexpected toughness and strength deep inside, thus creating a contrast. It's a mix of sweet appearance while having power and confidence hidden underneath, a sort of stereotype of a seemingly gentle girl showing explosive side of herself under special circumstances.