Girls with double buns hairdo. It is a ancient Chinese hair style, called 丫鬟 (literally: Y shaped hair style. Typically the hair style of young female servants). For some reason, I'm helplessly attracted to girls wearing this hair style.
This double bun hairdo, in chinese, is called 丫鬟. 丫鬟 today means female maid of the old era. But literally, it means, “y-shaped hairo”. It came to mean servant cuz that's hairdo of servants, presumably cuz maid not allowed to have fancy hairdo.