So I have a headcanon.
Aoyama doesn't like the dark.
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Tokoyami and Aoyama: *doing hero work at night*
Tokoyami: *walking along*
Aoyama: *holds his hand and clings to his arm*
Tokoyami: *looks at him* you okay?
Aoyama: yeah-
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Tokoyami: okay sleep.
Aoyama: fine.
Tokoyami: *turns the light off and flops on his bed*
Aoyama: *snuggles up to him and holds him tightly*
Tokoyami: *turns on a lamp* okay what's wrong-?
Aoyama: nothing- *moves away*
Tokoyami: 'is it the dark-?' *turns the lamp off*
Aoyama: *clings to him again*
Tokoyami: *turns the lamp on* you scared of the dark?
Aoyama: *nods*
Tokoyami: you should of said something. I'll keep the lamp on.
Aoyama: *smiles* *eventually falls asleep with his head on Tokoyami's chest*
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-when they doing hero work at night-
Tokoyami: *immediately holds Aoyama's hand*
Aoyama: *clings onto his arm*
Tokoyami: it's okay. I've got you.