Using pre-activated eSIM once arriving in Japan?

Hey all,

Is using an eSIM as simple as activating it before I leave and then selecting it as my active sim once I've touched down? I tried that on my last trip and my ubigi esim just never activated so I ended up having to purchase one at Narita T2 and getting the employee to activate one for me. Are there any extra steps that I might have missed? I'm travelling again in march. Thanks.