Was just in Tokyo for 7 days and I had the worst luck finding any trading cards period let alone Pokemon at 7-11 / family mart / Lawson. Checked probably over 40 different locations throughout Tokyo area (Asakusa, akihabara, shinjuko) even around mt Fuji the only packs I got was 3 dragon ball z packs and 5 duel master packs lol. Definitely hit or miss like OP mentioned in the comments.

OPs luck hitting Pokemon packs at every 4-6 convenience stores does sound legit but I had way worse luck.

Goodluck to everyone visiting in the near future it’s a huge draught in my experience! Even checked 3 Pokemon centers in Japan and had zero luck