Ai shiteru: I love you

Arigato: thank you

Baka: idiot/dummy/retard

Bakayaro: Moron

Bishounen: beautiful male.

Chan: suffix for dear (i.e. Hee-chan)

Chibi: little/small/mini

Chotto: just (used with "matte")

Dare: who

Doko: where

Dooshite: why

Domo: but

Ecchi: Perverted, gross, squick

Gomen: sorry

Hentai: pervert, perverse (like ecchi)

Hai: yes

Ja ne: informal goodbye

Iie: no (almost never used because it is considered impolite)

Itsu: when

Kami: god

Ki: life energy (a.k.a. chi (chinese))

Konban wa: good night (polite)

Konichi-wa: hello (polite)

Kun: sign of respect. Used for boys most of the time.

Kuso/Chikusho/k'so: shit

Manga: Japanese comic book

Matte: wait (as in "chotto matte", wait a minute)

Minna: everyone, people (hello minna!)

Mirai: future (ex. Mirai Trunks (the guy is hot)

Moshi Moshi: hello (used in phone conversations)

Nani: what

Nasai: very

Ne: okay

Obaasan: grandmother

Obasan: aunt

Okaasan/Kaasan: Mother/Mom/Mama etc.

Ototochan/Totochan: younger brother

Ohayo: good morning (not as formal as Konnichiwa)

Ojisan: uncle

Ojiisan: grandfather

Onna: woman (Wufei uses this word a lot ^__^)

Oneesan/Neesan: sister

Oniisan/Oniichan/Nichan: brother

Otaku: obsessed fan of anime (like meeeeeeee)

Otousan/Tousan: Father/Dad/Papa/Daddy etc.

San: Mr., Miss, Mrs.

Sama: title of great respect

Sayonara: goodbye (polite)

Sensei: teacher

Senshi: soldier (ex. Sailor Senshi)

Shenlon: dragon (Wufei’s Gundam is the Shenlong)

Shimatta: damn

Shinnigami: The God of Death (in other words, Duo)

Shojo ai: girl love

Shounen ai: boy love.

Sugoi: wow! Cool! (like yosh)

Yaoi: male/male situations (sexual)

Yatta: We did it! Or You did it!

Yosh: Great!

Yuri: female/female situations (sexual)