(NOT NAGISA but could be) you live in a world where more species are emancipated. But not everyone is on the same level. Humans are still the dominating species and you, an incubus/succubus, are one of the most despised species

You're snuggling in a box in a rainy day. You can shapeshift in order to fit the tastes of others. You've been trying to find a form that is cute enough for people to take you in. Until a soft looking boy runs along with an umbrella "hi! Is everything ok?"