oni-chan 

A Japanese mating-call that is often used in Hentai.

Hit me harder oni-chan!!!

oni-chan by redrenagade February 3, 2017

Oni-chan 

A way to say, “brother”.

Often used as, “Yamate oni-chan!”

Oni-chan by Bung33cum May 23, 2021

Oni Chan

A word in some Japanesse animes "specificaly used by lolies" for "big brother"

"Big brother"(oni chan) Can you tuck me into bed"?
Big brother (oni chan) Can you help me out of the dryer"?

Oni Chan by Miku kinnie September 8, 2020

Oni Chan

A word typicaly used in Japanesse animes by younger female anime girls to their older brother or just by anoying weeaboos who think they know the whole damn language.

"Oni Chan (big brother) can you make me a glass of milk?"
"Oni Chan (big brother) can I watch TV with you"

Oni Chan by Miku kinnie September 8, 2020

Oni Chan

When you love your brother so much!

'Ohayo, oni chan~'

Oni Chan by yourlocalcatgirluwu May 3, 2022

oni chan

basically stepbro

omg oni chan nooo

oni chan by youwantpen March 9, 2021

Oni chan I have dick 

This term is used in Japanese hentai normally filming a young child with a fold man this man is ready to have sexual intercouse with the young child (which in the west is considered pedophile) this man is then told “oni chan I have a dick” normally the man is not phased by this and goes in for the tight pum.

Oh oni chan I have dick if you forget

OH THAT DOESNT MATTER LOVE
The man below is a know sex offender

Oni chan I have dick by Dengplural December 9, 2019