The date is a pun:
Miko → mi(3) ko(→go; 5)Personification♂→The otoko no ko Ghost-Half-chan, who got asked to act as a stand-in for a miko out of nowhere.Hey... Even if I'm a guy, is it still ok for you (that I act as a miko)?Y... You won't get angry at me, right?InsideMale mikos may be called "otokomiko" or "okannagi"!
Otokomiko is basically a portmanteau with "otoko" (male). Kannagi (or, okannagi as it is here) is a word that can be used for both genders, but the kanji it is written with is apparently different (巫 for females, 覡 for males).
