Merch wise, always check places like Etsy where small sellers can post their stuff. I took a quick look myself and there's some merch for Codenane Anastasia. Maybe try there?
You can trying searching proxy sites/businesses. Idk where in the world you’re located at but it’s not Asia, which is unfortunate because all of the merch you’re wishing for is probably only being sold in Asia. My only advice is to do your research on the proxy business you’re giving your money to. I found some Codename Anastasia merch. But lowkey I hate this proxy business, and I’d rather not send anyone towards their way, unless it’s you want it as a last resort. Cause they could be making you wait 6 months like they’re doing to me. Try looking at manga stores, figurine stores, and proxy businesses.
Ok, if I like a series enough, I want to buy merch. Lately like 99% of series I read are webcomics and a lot of the, have merch, even some I wouldn’t think are that popular, the sad part is that most of the ones I’m reading and would love merch for don’t have any :(
Of the ones I think are popular, I’m surprised they haven’t made physical releases for Codename Anastasia. I’ve gotten the physical copies of the Passion novels and manwha and Roses and Champagne even got an official English release, so I’m surprised there have not been any news of any physical releases for Codename Anastasia.