owlteria:

Wow.
I was having the same thought some days ago and I was asking myself exactly the same
thing. This is cool! 😀

In one of my headcanons, Siegfried has a bipolar
disorder with occasionally psychotic symptoms, so it’s possible that
he would cut his hair since it’s a
form of self mutilation.
He’s
mutilating his hair when he doesn’t find better ways to handling
stress or when he doesn’t know how to cope with his inner panic and
anxiety. It usually occurs when he refuses to take his meds and a
manic depression’s taking its toll on him.

Also his short face
framing bangs are the result of some earlier manic episode where he
cut off some strands. First it was only one side, but he later had to
adjust the other side to the same hair length for correction, so it
wouldn’t look too weird. He was pretty sad and ashamed though, when
he realized what he’d done, because he loves his silky hair very much.
However, Siegfried got used to the short bangs and he accepted them
as his personal style and nice highlighting accent to his long
straight hair.

Good
luck for Siegfried, it’s just hair, it doesn’t hurt and it grows
back. However, it’s the kind of behaviour which worries Kaiba, but
it’s nothing compared to the moments when Siegfried’s desperately sharing his suicidal thoughts with him.