A "halvsie" is an unofficial term for a person who is half-Japanese. The term originated in Japan and was coined to replace the more general "hapa."
John: "What is your ethnicity?"
Aiko: "I'm a halvsie, my father is white."
mixed genitalia; half of a penis.
"I was hooking up with this chick, and then I had to run away because she had a halvsie!"