Multi-region (US, UK, EU, Asia), can one Magento serve all of them?

Yes, via store-view-per-region. The comic-books vertical has specific multi-region quirks:

• US, primary market. Diamond + Lunar Previews, USD pricing, US tax (sales-tax-by-state via Avalara or TaxJar), USPS/UPS shipping. Subscription bundles standard.
• UK, Forbidden Planet is the incumbent. GBP pricing, VAT-included display, Royal Mail shipping. UK manga share is higher than US (~30% vs 20%).
• EU, fragmented (separate Italian, French, German manga publishers like J-Pop, Glenat, Carlsen). EUR pricing, country-by-country VAT, DHL/DPD shipping. EU customs since Brexit complicates US-to-EU shipments, IOSS registration required for parcels under €150.
• Asia (Japan, Singapore, Hong Kong), manga readers buy English-language editions when they want lettering vs. original Japanese. Customs paperwork heavy; international shipping rates ~3x domestic US.

Magento Multi-Source Inventory (MSI) handles inventory per region. Store views handle currency, tax, language. Manga MAP enforcement varies by region, Viz US discounting rules differ from Viz UK.

The piece most LCS owners under-plan: customs documentation for international shipping. Each shipment needs HS codes (4901.10 for comic books, 4901.99 for graphic novels) and a commercial invoice. Magento integrates with EasyPost / Shippo / ShipStation to auto-generate this paperwork.