Because you like Spike in Buffy the Vampire Slayer

Eren Jaeger will erase the Titans from this world until not a single one remains. See them in Attack on Titan.

What Mako Mankanshoku lacks in common sense, she makes up for in sheer optimism and force of personality. See them in Kill la Kill.

Killua Zoldyck is so tired of killing. He just wants to be a kid, hanging out and doing stuff with his friends. See them in Hunter x Hunter.

Freelance writer Diane is dating a dog and writing a memoir of a horse. See them in Bojack Horseman.

Undercover as an average high school student, Kallen Stadtfeld is actually most at ease when the action's fast, furious, and dangerous. See them in Code Geass.

For Celty Sturluson, it's rather upsetting to be the only headless girl in a city filled with full-bodied humans. See them in Durarara!!.