Recommended order
For a first-time viewer, start with the 2011 television adaptation and watch it from episode one through its full run.
Treat recap or special material as optional unless you specifically want supplementary content.
Quick advice
For a first viewing, use the main television series in release order unless an official release or licensed platform presents a different intended sequence. Avoid skipping canon episodes simply because a list labels them as optional without checking the context.
Explore more
Episode availability and regional catalogs can change. AnimeZax provides spoiler-light editorial guidance and does not stream episodes.