The tag counter has some contrast. In two and a half years Kancolle reached more than a quarter of Touhou tags (131k vs 469k). Then in 8 years of time (since Mountain of Faith launch) Tenryuu got tagged 60% of Nitori count (6k vs 10k).
Let's see what PIXIV tags tell. 「東方」 1849k (not counting 56.5k tags for 「東方Project」 as both overlap). 「艦これ」 378k (not counting 262k tags for 「艦隊これくしょん」 as both overlap). 「河城にとり」 23k 「天龍」 + 「艦これ」 18k
For a game which lifetime will be shorter than Touhou it's rather impressive.
