The mascot of the town of Onomichi from Sega's long running game series, Yakuza, known in Japan as Ryū Ga Gotoku.
Note that Onomichi is a real life town, but Ono Michio is unfortunately not
Ono Michio: With my charming hassaku face! Steaming Onomichi ramen hat! Cute fish pouch! Cool boots, vital for any fisherman! And my bold and trendy Ono shirt! That's right! I'm the pride of Onomichi...
Ono... Michio!
Any follower of Yoko Ono who believes in everything she says no matter what just because she was John Lennon's wife. (People who wouldn't give a shit about her if she wasn't with John wouldn't count as Ono Leeches.
"Oooh, I just got this new Yoko album!!"
"If it weren't for John, she wouldn't even sing, let alone get a record deal."
"Don't say that! She's amazing!"
"You're such an Ono Leech"