早弁: (slang) eating lunch before lunchtime

oh my

千早人: allusion to 宇治 (Uji, “a placename, especially of a river crossing”)

a hostage / (archaic, original sense) indentureship, the state of being in servitude to another as collateral on or payment of a debt

urban myth; urban legend

shaved ice lightly flavored with matcha green tea and topped with boiled azuki beans

already, now

dace (carp)

an ancient ethnic group living around the Ōsumi, Satsuma region of Japan

a surname