The term "waifu" is a word that is used prevalently in the Manga/Cartoon, and Video-game fandoms. The origin of the word comes from the katakana word for wife; ワイフ
However, Japanese-speakers will never use that word. The real word for wife is 妻 (tsuma/
sai).
"Waifu" is used to refer to a fictional girl or
woman (usually in
Anime, Manga, or video-games) that you have sexual attraction to, and you would even marry.
Remember; "ワイフ waifu" and "妻 tsuma" are completely different. Waifu is a
joke word that Anime fans call fictional
female characters that they love and would marry if they were real. Your tsuma is your real wife. That is the real Japanese word for wife.
Example of waifu:
"Do you like Camilla from Fire Emblem Fates?"
"I LOVE Camilla! Her large breasts, her curves,... she's my waifu!" 😍
(This guy has sexual attaraction towards Camilla from Fire Emblem Fates. He would even marry her if she was
real, he called her his "waifu"
Example of 妻 :
私は今日結婚しました これは私の妻キコです
「I got married today. This is my wife Kiko.」
(A man was married to Kiko that
day. She is
real, not a fictional character. The
real Japanese word for wife was used.