When was the Day of Severance?

Question

We know that the Day of Severance had to have happened some time after Kureha was born. Indeed, it must have occurred sometime after Ginko and Kureha became friends (i.e. after they met on the snowy battlefield past the Door to Friendship), since they could not have become friends in the first place had Severance already occurred.

We also know that the Day of Severance happened before episode 1 of the show, because, of course, that's how the narrative begins in the first place. I'm pretty sure that Severance was also before Ginko and Lulu met.

Can we pinpoint when the Day of Severance happened any more accurately (relative to other events in the story)? In particular, it's not clear to me whether the Day of Severance was before or after the day on which Reia sent Ginko back across the Door to Friendship.

(Or maybe I've got this all wrong? In episode 11, the way Kureha's classmates harass her about her friendship with bear-Ginko [during a flashback] seems to suggest that the Day of Severance had already happened - so does that mean that the Day of Severance even precedes the day on which Kureha went across the Door to Friendship to fetch Kureha from the snowy battlefield?)

Answer 1

I believe the Day of Severance is the day Ginko is sent out into the battlefield . Before this, tensions were rising at each side of the Wall - The young bears were brainwashed into thinking fighting in this battle would gain Kumalia's love, And you can see the human's disdain for bears when Kureha is picked on as a child for being a 'bear-lover'.

The Wall of Severance was erected after the battle (hence the Day of Severance) to separate the two worlds.

There seems to be an oversight in the plot in regards to the Door of Friendship and when it was built, which is what I personally found confusing. It appears that the door of friendship was built prior to the day of severance, but only discovered in the midst of the battle. It does seem a little odd how this portal was overlooked for so long if it already existed, and what use it served without the wall in place.

Neither world seems to know much about the portal, it seems to be a only known about by Ginko, Kureha, Reia and Lulu. One theory is it could have been built by Kumalia, another is that it's a plothole.