Noa:
The World Is Ugly - My Chemical Romance ( noa x tadao )
Stand In The Rain - Superchick ( noa's breakdown in season 1 )
Dressed In Black - Sia ( general )
E.V.O.L - Marina And The Diamonds ( despair!mode noa x tadao )
Runaway - Hail The Villian ( secret spoiler-ish )
Hello How Are You - Miku Hatsune Soft ( noa opening up in season 1 )
I Am Not A Robot - Marina And The Diamonds ( noa opening up in season 1 )
Redundant - Green Day ( noa x tadao )
This Night - Black Lab ( secret spoiler-ish )
I Miss You - Blink 182 ( noa x tadao )

Tadao:
Love Me Dead - Ludo ( noa x tadao )
Sins Of My Youth - Neon Trees ( general )
The Horror Of Our Love - Ludo ( kinda spoiler-ish for noa x tadao pre despair )
Everybody Talks - Neon Trees ( noa x tadao )
Runaway - Hail The Villain ( noa's secret spoiler-ish )
Redundant - Green Day ( noa x tadao )
I Miss You - Blink 182 ( noa x tadao )

Suzume:
Funeral Bell - Phildel ( just about death in general, the killings )
Superstitious - Stevie Wonder ( her SHSL ability in general )
Black Lilliana - Umineko No Naku Koro Ni OST ( background music for execution )
Round And Round - Imagine Dragons ( the killing life )
Bones - MS MR ( her SHSL ability, a reading )