Armeyer Dinze is the main character and titular character from the series. She's a merchant.
In Ragnarok Online Edit
In-game, Armeyer is a mob located in the second floor of Biobals, the dungeon of Lighthalzen, introduced in Episode 8. Doing quests related to Biolabs reveal that the Rekenber Corp has been doing a controversial research about the secrets of life, with implications of human experimentation, which is likely why she and the other ghosts are around the place.
In order to access the Biolabs, the player must complete the Biolabs entry quest, can be found here. To start it, your character's level base must be 60 and on wards and you'll be able to start it.
Most of time, Armeyer has a cute, bubbly personality towards people and specially towards her "big brother", but she also has a more unstable side; when she becomes attached to someone very much, she'll become dependent. So much that she'll try to get rid of any one who gets in the way of her object of affection and her.
Her obsession can reach to very dangerous levels, and might go through violent acts, though she'll panic when she comes in her senses. Armeyer seems to genuinely enjoy innocent pleasures like candy and stargazing.
She was born in Lighthalzen. At some point of her life, she agreed to follow Howard and hasn't let him go ever since, and perhaps due his suggestion, she became a Merchant.
Howard Alt-Eisen - They're very close to each other, and Armeyer considers him to be the big brother she never had. She seems to be obsessed with him to some degree, though.