A stock phrase in Japanese pop culture supposedly used by the wife in a newly-wed couple to invite her new husband to bed.

Kyūjitai form of 私生児 (“illegitimate child”)

(Buddhism) think on the power of Kannon

an enemy / revenge, vengeance / opponent (of the game or conflict) / (archaic, obsolete) marriage partner

difficult

a Japanese anchovy (Engraulis japonicus) / (by extension) any anchovy

片口鰯: a Japanese anchovy (Engraulis japonicus)

one-way / one-sided / one-way ticket, short for 片道切符

feeling small, ashamed, unable to hold one's head high

it is easier said than done