|Light Novel||Web Novel|
One of the founding guild members of Ainz Ooal Gown and one of the only two female members of Nine's Own Goal. Her character name, Yamaiko, is a reference to Maruyama's first published work , the short story Dawn in Kagetsu Tohya  . Her real name is Yamase Maiko, and Akemi as her little sister is also a reference to this as well .
Web Novel Edit
Arcadia 2878: Old fans of Type Moon will know it but I wrote ’Dawn’. They also will know Yamaiko-san’s real name. 
- ↑ Volume 1 Author Thoughts: Although there was a case of giving up the dream to be a novelist in my introductory published work, that is the adoption of my short story ’Dawn’ in Kagetsu Tohya...
- ↑ https://typemoon.wikia.com/wiki/Kagetsu_Tohya
- ↑ https://en.wikipedia.org/wiki/Kagetsu_Tohya
- ↑ Blog: Q: Speaking of which would [stuff from] Ten Nights of Dream’s Dawn come in [Overlord’s canon]? A: Yamaiko-san’s full name is Yamase Maiko and has a beautiful younger sister named Akemi, its a different person from the character in ’Dawn’ . Rather than using a name is no problem at all but for Dawn to come in.....
- ↑ Dawn: At the top of the stairs were the doors to two rooms. ’Maiko’s Room.’ And then, ’Akemi’s Room.’
- ↑ Prologue 1: This was Yamaiko, the nephilim.
- ↑ Prologue 1: This was Yamaiko, the nephilim. Unlike giants, who were demihumans of a sort, nephilim could not hide their ugliness no matter how they tried to disguise themselves. It was hard to imagine that within that body was the only other female member of the group, besides Bukubukuchagama.
- ↑ Volume 11 Character Sheet
- ↑ Volume 8 Story 2: At the very most, they had invited the little sister of the guild member Yamaiko — whose player name was Akemi-chan — a few times.
- ↑ Arcadia 2878: Old fans of Type Moon will know it but I wrote ’Dawn’. They also will know Yamaiko-san’s real name.