[shmaster]

The plot thread about Kureha's mother, and the Relic that was buried beneath their town.

Spoiler:

Kiriya's mother died protecting Kiriya in a past attempt in trying to reboot that Relic. Kureha and Sheena both witness what happened, but Kiriya himself has no memory of that event.
Ever since then, there exists an uneasy silence between Sheena and Kureha beneath the table.

Kureha's mother has been trying to get Kureha marries either Souma, Kiria, or Triheart to further her plans on the Relic. But as we know, Souma and Triheart both are staying in Endias, with Kiria as the only choice left. Which also is not a easy case with all the Secty love behind him. I doubt Kureha's mother is going to stay silent. They really need to put an end to that Relic or else Kureha's mother is not going to stop scheming.