And “analogous” means “similar”, not identical.

So what’s your point?

Being a hikikomori also precludes immediate family members including parents, spouse, etc.; you often don't even leave your room let alone your house/apartment.

Hikikomori is a level or two beyond what most westerners would think of when imagining an extremely introverted or reclusive person. The condition is more akin to PTSD stemming from severe mental/social trauma.

For further context, the etymology of hikikomori is to "hiku" (literally "pull", contextually in this case to "pull back" from daily life) and "komoru" (to "shelter up", in this case most likely sheltering in your bedroom or mancave or similar safe space).

Well, no. Hikikomori isn’t an all or nothing state of being.

What makes the news and what makes it to the Western media are the most extreme cases.

The actual development to the extreme (or not) can be quite gradual.