Does entry ID change with locale? I have a condition that checks entry Id. The condition seems to not work for Japanese locale but works fine on English. I would think that entry ID remains the same irrespective of the locale. Please confirm or correct me if I'm wrong. 

Thanks!
The ID won't change in different locales, check this answer for reference: Craft 3 language switcher

You could also test it in your templates e.g. :

{% for locale in craft.app.sites.getAllSites() %}
    {{ craft.entries.siteId(locale.id).one().id }} : {{ craft.entries.siteId(locale.id).one().title }}
{% endfor %}