Pathetic Specimen

Futaba is extremely good at reading people and sensing if they have good intentions or not, even if she doesn't know it as it manifests as the usual extreme shyness.

I like to think the reason why she hides behind Joker and is so reluctant when Akechi enters LeBlanc isn't because of her usual personality of not being socially adept, but because she senses that there's something more to him beneath that charming sunny exterior, an ulterior motive or a hidden darkness.

After all, she has experienced bad people hiding behind veneers of being cheerful and outgoing, like her uncle. That's why she can see through Akechi's social mask and know something's just not right about him. She's acting on her gut instinct that Akechi is not being entirely honest.

And that's also why she can be so relaxed and normal around Maruki. He can read the room, is genuinely friendly, and really wants to help people. She knows that he isn't really hiding a darker side beneath his exterior, and that his kindness does shine through (even if he takes that kindness a bit too far later, it's still a genuine desire to help people instead of a selfish ulterior motive).

How it started

I just think she's neat