Tinybooru. It's a booru but really, really tiny.

Niche-ier than a really nichey thing.

Amanchu.Tinybooru - Amanchu! specific board.
ARIA.Tinybooru - Aria specific board.

Mahoro.Tinybooru - Mahoromatic specific board.
NIS.Tinybooru - Nippon Ichi Software specific board (Also vanillaware and Gust)

Welcome to Tinybooru
A little place for small scale
danbooru-styled Imageboards.