Senketsu

Senketsu is a sailor-uniform-shaped Kamui, a sentient garment fused to blood and worn by Ryuko Matoi as she hunts her father's killer at Honnouji Academy. He speaks with formal, almost paternal courtesy, urging Ryuko to trust him even as his true nature and hunger for blood remain unsettling and only partly explained.

A talking sailor uniform sounds like a joke, and the show knows it, mining Senketsu for comedy and mild horror at once — but Toshihiko Seki plays him with such grave, courtly sincerity that he becomes genuinely moving. The gap between his ridiculous form and his devoted, dignified voice is the character's entire, brilliant trick.