honestly the best place to start is the official Sanrio shops. The Sanrio official global store and regional Sanrio webshops often have the newest licensed plushies, apparel, and accessories featuring 'Dear Daniel' alongside 'Hello Kitty'. Sanrio Puroland and Sanrio Gift Gate items are also gold if you can handle proxy shopping from Japan.
If you want more variety, big retailers like Amazon, eBay, Hot Topic, and BoxLunch pop up with collabs and exclusives. For Japan-only releases and vintage pieces, Mercari Japan, Yahoo! Auctions Japan (use a proxy like Buyee or FromJapan), Mandarake, AmiAmi, HobbyLink, and Rakuten Global are where I’ve found rarer stuff. Etsy and independent shops carry hand-made or custom-inspired keychains and art (watch licensing notes). When I buy, I always check seller ratings, clear photos, and return policies — and I search multiple spellings: 'Dear Daniel plush', 'Dear Daniel keychain', 'Hello Kitty boyfriend merch'. Hunting down the perfect 'Dear Daniel' item genuinely makes me giddy, especially when it arrives in the cutest packaging.