Much like several Social Links in Persona 3 Reload, Tanaka's Social Link is locked behind several prerequisites, making it easy to miss on a first run if you're not careful. He's an evening-only Social Link and is arguably one of the easier ones to Rank Up. If you're keeping up with the Hermit Social Link and your Social Stats, you'll be able to start the Devil Social Link around the midway point of Persona 3 Reload. Even if Tanaka isn't the most pleasant person to spend time with, you'll want to max out the Devil Social Link so that you can receive the ultimate Persona of the Devil Arcana.