there are 2 places, Heaven and Hell. Heaven is where Angels live and Hell is where Demons live. Angels and Demons are enemies with each other and since many years ago, there have been almost many wars between Heaven and Hell. But, one angel named Shizuku and one demon named Airi felt like getting along with each other and not fight

one day, Shizuku and Airi met up secretly without any angel or demon knowing

Airi: Hey, Shizuku!

Shizuku: Hello Airi~

Airi: Can I ask you something?

Shizuku: Sure! What is it?

Airi: If angels and demons don’t get along…then should the two of us…really fight with each other? she asks her a little worryingly

Shizuku: Hmm, well…what you said was true, Airi. she pauses for a moment, then continues to proceed But for us, we will never become enemies! We can still be friends, you know that? Even if I’m an angel and you’re a demon?

Airi: O-Oh! If you say so, Shizuku.