@criver I never said anything about trust though? I called her oblivious because she doesn't realize how the gyaru feels about her.
Well, most people don't usually assume that someone of their own gender has feelings for them. But if she had asked other people about those guys, she would have figured out that something's going on. Even without that, the "you still got me" phrase in the given context (love affairs) is sort of a hint.
So, what choice does the gyaru really have? She could try confessing, but since the naive girl isn't gay that could end their friendship. Helping her to find a boyfriend could lead to the same result - friends tend to grow apart after getting into relationship. And doing nothing just prolongs the inevitable, there's nothing but misery in the gyaru's future even without us shitting on her.