denfami's published a long interview with several of the core developers behind Avalon no Kagi/Key of Avalon, Hitmaker and Sega's 2003 Culdcept-ish arcade TCG—this game isn't necessarily held up as a pivotal entry in the genealogy of arcade card games (mostly because it simply appeared too early to take advantage of the network features that solidified similar games that came just a little later) but it's definitely a game that defines the specific transitory era of early-'00s Japanese arcades and one that paved the way for the likes of Sangokushi Taisen and Quest of D, and I've seen a lot of reminiscence about it over the last few months.
The interview covers all manner of topics, including peripheral topics about the politics behind using the Triforce arcade hardware, and how character-centric arcade projects are viewed with such reticence by upper management that devs were actively hiding their games' character elements from their higher-ups as recently as 2015's Chunithm, but one topic that caught my eye was the discussion around the game's community and official fan events which, due to the game being a poor match for large-scale tournaments (games take too long, basically), were centred around pretty much everything except playing the actual game, which ended up fostering a very unique and diehard community among arcade games. One of the signatures of these events was the presence of the developers themselves, who were all presented with some sort of obvious gimmick, the most notorious being designer Taguchi's gimmick of being a boozehound who was never without a drink... whaddya know, dude doesn't actually like alcohol all that much, but was locked into a character that meant fans were constantly wanting to drink with him and gifting him bottle after bottle, and one of the anniversary events scheduled for this month has a premium "buy a drink for the dev" ticket tier.
One much sadder anecdote: they tell a story about a certain community member known for their impressive card collection who, with the encouragement of the devs, ended up starting their own card store; that community member was one of the 17 victims of the 2008 Akihabara massacre, and members from the dev team attended their funeral.