"Katakana sound effects have long been a vital part of manga, with authors often using them lavishly throughout sequences to help heighten the visual mood of the story. It’s actually a really interesting topic of thought: designing typography based on the sound effect that each character has."
These striking rings are available through Mitsubai Tokyo. Prices range from smaller characters (ッ) which sell for 7,612 yen to larger characters (ド・ゴ・ハ・ガ) which sell for 23,100 yen.
[via Spoon & Tamago]