If it’s related to fuzoku (adult entertainment) , those often use numbers + letters. These are usually in Kabukicho (Shinjuku), Uguisudani, or Yoshiwara. Be aware of legality and scams (don’t follow touts).
The "Tokyo Hot" series is a well-known collection of adult videos produced in Japan. These productions are typically categorized within specific genres of the AV industry, often focusing on uncensored content, which distinguishes them from mainstream Japanese adult videos that are required to follow strict censorship laws regarding genitalia. tokyo hot n0210