The four silhouette characters, according to the article, are named: Ortapia, Heinmel, Rizweld, and La Worg. — see below!
More info from News Vault:
Eida (played by Haruka Terui) is the only daughter of the blacksmith, Kornha. She runs the Ryuusei Workshop, a weaponshop. Not only does she recognize Lyra’s crush, but she enjoys teasing her about it as well.
Sasha (played by Haruka Morimune) is the manager of the general store called Sunset, and she’s always looked at Nayuta like a little brother. She collects antique dolls, and thus makes outfits for them.
You will be able to buy items from them at shops.
The silhouette’d figures are four ‘managers’ of the continents of Lost Heaven-
The Continent of Forests, Ortapia – the manager is Lychnis (??) Gio, voiced by Tomohisa Asou. This is an island of beautiful forests.
The Continent of the Abyss, Rizweld – the manager is the Song Priestess, Elisrette, voiced by Miyuki Sawashiro. There are many underground caverns where water is collected, and devices that are controlled by waterwheels and such.
The Continent of the Sacred Mountain, Heinmel – the manager is the Guardian King Algol, voiced by Ryoutarou Okiayu. This continent is a mountain range with steep cliffs and an intense climate.
The Continent of Origins, La Worg – its manager is Sage Nemeas, played by Mai Aizawa. She apparently has ties back to Noi. This is a continent covered by flows of lava.